Fireside Friday: July 17th, 2020

Hey folks! Fireside this week; musing on a rather silly topic: the practicality of planetary invasions in a science fiction setting. I am working currently on (among other things) getting the “How They Made It” post series started up; those will be a set of post-series detailing how pre-modern societies made all of the stuff they had, with a special focus on the people who did the making, with the hope of – by slowly but surely accumulating workers – drawing a more complex and real image of what an ancient or medieval society might look like. My plan for that is to start with agriculture, textile production and iron-working (not necessarily in that order). I hope that will be interesting both from a historical perspective, but also for all of you fiction-writers and game-masters interested in historical world-building.

Before we dive into the musing, I do want to address the comments a bit. The last two posts have produced some contentious debates in the comments. I appreciate that, insofar as I have seen, everyone has remained civil (thank you; I don’t particularly want to have to wield the moderation powers, but I will if I must), but I did notice some rising temperatures, so I want to reiterate the importance of reading with charity. Not everyone writes in the guarded sort of academic style that is designed to be read by a hostile or at least sharply critical audience and so when we read our fellow commenters (or fellow citizens, or fellow humans) it is important to read from that place of charity. Yes, there are bad-faith arguers out there (fewer, though, than is sometimes supposed), but for the most part, we’re discussing these things in good faith and we should lend each other the benefit of the doubt. Everyone is wrong from time to time, even me.

That said, just to make sure it’s clear going forward: there will be no ad hominem attacks, harassment, flame wars, or anything of that sort in the comments. My rule of thumb is that if I wouldn’t allow it in a classroom discussion, I won’t allow it in the comments. So far, it looks like everyone has comported themselves well enough; please continue to do so. Otherwise…

The Pedant looking stern in his academic regalia (so kindly purchased by his better half as a graduation gift) and showing that the best dissertation defense is, in fact, a good dissertation offense. I should also note that is not my trebuchet; it also belongs to my better half.
As an aside, no we do not get these fancy academic gowns for free on earning a Ph.D. They are, in fact, hideously expensive – had I been surviving on my stipend and teaching income alone, I would certainly have been unable to afford them. Few of my colleagues could.
Fun story, while we’re here – when I graduated high school, a couple of my teachers (who had Ph.Ds) attended the graduation ceremony in their academic regalia, which included the academic tam (that floppy hat I’ve got on); my nerdy friends and I were entranced by the fact that they got to wear something other than the silly mortarboards we and everyone else was stuck with. I very much wanted one; my wife moved heaven and earth to make sure I’d have mine in time for my Ph.D graduation (there having been a problem with the supplier), quod ea optima uxorum est.

For my musing this week, I actually want to muse about this video and the points that it raises, particularly because I think the video’s creator, Spacedock, has gotten firepower wrong in a very common way. To summarize, Spacedock’s argument is that planetary invasions would never happen because the firepower advantage of an orbiting hostile fleet in any science fiction setting is so great that any planet would be forced to surrender and that consequently science-fiction armies would be minimal mostly-all-infantry garrison forces.

And that makes some assumptions about the effectiveness of aerial (or orbital, in this case) firepower which are worth digging into.

The first major point is to consider is what is being fought over and why. While we often talk about conquest in terms of ‘land’ in practice since the agricultural revolution – and increasingly so since then – the primary resource one aimed to conquer wasn’t just land but the productive population and infrastructure on that land, either to directly extract resources (tribute extraction) or to use the population as a supply-base to support forces aiming to establish control over the region in order to keep other productive regions safe (think fortified Roman frontiers that are held not because they are productive, but because they are in between enemies and the really productive areas – nevertheless, depopulate the frontiers and you leave no logistics base on which to station an army).

What that means is that strategic objectives are likely to impose sharp limits in the ability to use orbital firepower if the goal is to control the planet or even to be able to meaningfully extract resources from it. Blasting a world into uninhabitability using nuclear munitions or even just de-orbiting large rocks may be strategically unacceptable. Moreover, defenders are likely in many cases to know this and plan their defense accordingly, much as modern non-state fighters plan knowing that conventional military firepower is often more limited in densely settled areas. Modern conflict is heavily constrained by the inability to fully deploy modern firepower without sacrificing strategic objectives; there is no reason to think that would change in a space war.

This then ties into the second point, which is the limits of firepower against infantry forces using cover and concealment. How much firepower do you need to remove deeply entrenched infantry? A lot, it turns out. Stephen Biddle (you may recall him) wrote a piece in Foreign Affairs (82.2, 2003), “Afghanistan and the Future of Warfare” where he laid out some statistics for firepower against entrenched infantry. He noted, for instance that “French defenses at Verdun in 1916 endured a two-day German artillery barrage equal to about 1,200 tons of explosives — in nuclear parlance more than a kiloton, or more explosive power than the w48 tactical nuclear warhead — yet enough of the entrenched defenders survived this maelstrom to halt the German assault [emphasis mine].” And “On July 18, 1944…[the allies] deposited…more than 8 kilotons of firepower — on just seven kilometers of German frontage in less than three hours [emphasis again mine].” In both cases, there were enough defenders left not merely to fight, but to actually win both battles. Nor is this merely a feature of old dumb-bombs; in Afghanistan, Biddle notes, “One dug-in al Qaeda command-post was found surrounded by no fewer than five 2,000-pound bomb craters. Still, its garrison survived and resisted until overrun.” In short, it is possible for infantry – with only improvised field-fortifications – to sustain energy delivery on the level of tactical nuclear yields and not only survive, but be fightable at the other end.

(Note, 2,000-pound bomb here refers to total weight, not the explosive weight. I don’t know what bombs were used here, but the Mark 84 is a decent candidate, in which case the yield of all five of them would have been around 3.2 tons of TNT (5 bombs each with 945lbs of Comp-H6, which is c. 1.35x the explosive power of TNT)

Now if we are assuming two sides at rough technological parity, we should assume the defending planet has probably prepared for this possibility. There are likely to be hardened, bombardment proof shelters, not only for soldiers, but also for civilians. In that case, an attacker might be looking at a situation where an orbital bombardment would annihilate functionally all of the expensive ground-based infrastructure (roads, fields, irrigation, factories, pipelines, buildings, etc.) that they hope to capture and still not effectively remove the defenders or damage the population. Prepared positions and concealed forces can absorb truly astounding amounts of firepower and still be ready to fight on the other end.

Which brings us to the third point, which is actually my main point: surrender. We’ve established that against a prepared enemy simply annihilating the defenders is going to be very difficult. So what are the chances of getting them to surrender entirely through orbital (or aerial) bombardment? I feel the need to point out – to quote Winston Churchill – “this has often been thought of before.” Going back to Giulio Douhet in 1921, strategic airpower advocates have long been promising that aerial firepower (in the form of bombing) would render ground combat obsolete precisely because the sheer firepower or the threat of firepower would force the enemy to surrender. The exact mechanism was that aerial bombardment of sufficient scale would erode enemy will to fight, particularly in the civilian population.

That model (which was promoted not only by Douhet, but also by strategic air-power advocates in the Luftwaffe, the Royal Air Force and the US Army Air Corps and later Air Force) was functionally tested repeatedly and it has not worked once. No civilian populace (note: not military junta or dictator) has ever been persuaded to give up on a war effort because of aerial bombardment in the absence of political pressure or ground operations. Post-War studies of ‘morale bombing’ in WWII (that is, the bombing of civilian centers, both by German and Allied airpower) suggested that far from bringing the bombed civilians to the table, aerial bombardment hardened resolve to continue fighting. Only in Japan did it lead to surrender and there not because the civilian will to fight broke (it doesn’t appear to have) but because nuclear attacks convinced the leadership that further resistance was impossible. Efforts to ‘win from the air’ by ‘degrading the will of the enemy’ through either surgical leadership strikes or civilian bombing have failed, in Vietnam, Afghanistan, Syria; in an odd exception, it sort of worked against Serbia, but to a significantly diminished degree than anticipated (and once again, the decision came from leadership, not collapsing public morale). Morale bombing does not work.

Somewhat ironically, Spacedock in his video gives one real-world analogy for why he thinks no one would ever need to do a planetary invasion, which I quote:

It doesn’t matter if you’re ten guys with rifles or five hundred guys with rifles on a tiny island, if there’s a giant battleship parked next to the island, none of the eventual outcomes involve an invasion of the island.

Which is just a real howler as students of the Pacific Theater of WWII will be well aware, because this exact situation happened, over and over again – the only eventual outcome did involve an invasion of the island literally every time.

So it seems likely to be that for a spaceborne force looking to exert control over a planetary population, landing ‘(space) boots on the ground’ is in fact likely to be the only solution. At the very least some forces would be required to target those attacks; one of the revelations of the air campaigns in Iraq and Afghanistan is that even 24/7 drone surveillance can be inferior to boots-on-the-ground reconnaissance in identifying and calling in strikes on targets (as Biddle discusses in the article mentioned above).

More broadly, you would need garrison holding forces. Spacedock allows for this but I think undersells the importance of that. He’s assuming that means light, almost purely infantry forces – effectively military policing forces. But even a brief glance at military action against relatively lightly armed (that is, lacking armor or air assets, to be clear) insurgents in Iraq and Afghanistan shows that counter-insurgency forces are not simply ‘some guys with guns.’ You need not only regular transport vehicles and logistics but also hardened MRAPs, IFVs, artillery and air-support (which is going to need to be fast and local, not slow and orbital). Even armor has a role, as the Syrian regime has shown to horrifying results, using even outdated tanks to ‘bully’ FSA forces who lacked anti-armor capability. Which is to say that occupation forces would likely resemble the full-spectrum armies that Spacedock is contending would not be necessary in a science-fiction-future.

But in the broader sense – and this is a key takeaway – the amount of firepower necessary to destroy a defense absent of ground forces is so high that there wouldn’t be anything left to occupy. Whatever thing of value was being sought would also be destroyed, it a logistics base, an economy, a population or even potentially just a habitable biosphere. And while ‘morale bombing’ has been offered, since the 1920s as a workaround for this problem, attempt after attempt to operationalize morale bombing has shown that not only does it not work, it is counterproductive. So far, the only way to apply force with the necessary precision to defeat a society’s defenders while keeping the society (which is the thing you want to control) is ground forces – and more narrowly infantry ground forces.

All of which is a complicated way of saying: you would still need to be able to land significant conventional ground forces in order to control the planet, its population and its resources.

Now, does any of that matter? Not to the question of science-fiction battles, no. Fiction can be whatever it wants to be. But I think to broader modern security questions, it does matter. Public overconfidence in the ability of high-tech firepower to simply obliterate enemies leads directly into advocacy for ‘easy’ wars which will be anything but. Firepower – and airpower – are of course very important in modern warfare. But it is crucial to remember when the next prophet of decisive firepower or decisive airpower shows up that such prophecies are frequently wrong and for the public to thus be skeptical that some new technology offers ‘painless’ victory.

At the same time, public assumptions that enemy will can be degraded by massive brutality plays into a narrative that we could win our wars if we only ‘took the gloves off’ – an assertion often made, but one which history does not appear to support. We touched on some of this when discussing chemical weapons. But the Syrian Regime ‘took the gloves off’ to a greater degree than any NATO military ever could (or would, or should) back in 2011 and they are still fighting, despite beginning the conflict with huge advantages (like near total airspace control, or having nearly all of the tanks and heavy weapons, or superior outside support from Iran and Russia). Rampant brutality did not, in fact, relieve the Syrian Regime of the need to send in infantry; one might argue that infantry in the absence of brutality would have served as well (with the caveat that the Syrian Regime was, in part, struggling under a severe manpower shortage and reverted to monstrosity to compensate).

For that reason, I thought those assertions were worth challenging.

On to Recommendations:

I would be remiss if I did not begin by recommending this live reading/performance of Aristophanes’ Clouds, with its opening discussion. The performance itself (done in English translation) is wonderful for bringing the energy and humor of Aristophanes to life. I’ve never had a chance to teach Clouds (but I have taught Lysistrata in translation) and I find students are often caught pleasantly off-guard by how modern and fresh Aristophanes’ humor can feel. Give it a listen!

Also, I finally got around to watching Hamilton on Disney+. You should also get around to watching Hamilton – it has been a very long time since I have been so pleasantly surprised by having something live up to its billing so completely.

Likely a number of you are aware of the developing story of the fire aboard the USS Bonbomme Richard (a Wasp-class amphibious assault ship designed to support amphibious operations). The best piece of writing for understanding the implications of the fire I have read is this piece by Bryan McGrath over at War on the Rocks. What I like the most about this article and why I recommend it are the opening few paragraphs which begin by explaining USN force structure and how the Bonhomme Richard fits into it. A lot of writing on national security issues and geopolitics really fail to capture these points; journalists writing for a public audience don’t include them because they either do not know them (frustratingly common, it seems) or because they want to spare their readers the sticky details, while analyists writing for the nat.-sec. community often leave them out on the assumption everyone already knows them. It can make it hard for the lay-reader of nat.-sec. or geopolitical news to move from facts to wisdom in understanding how those facts fit together.

Finally,as always, I’ll close out with a book recommendation, this time moving to the modern world with J. Stearns, Dancing in the Glory of Monsters: The Collapse of the Congo and the Great War of Africa (2012). There are a number of reasons to recommend this book. First, it presents a major conflict that, by and large, most people know very little about. The Congo Wars are often the ‘biggest wars you’ve never heard of’ or only barely have some limited sense about. Stearns’ book is an excellent ‘this is what happened’ primer for someone (I put myself here) who had little idea of the facts of such a complicated conflict (seriously – Stearns puts a table of abbreviations just for all of the militias involved; be sure to put a sticky-note on that page you so you can find it quickly).

But more broadly, Stearns’ book is excellent because of how relentlessly it resists easy answers. There are many villains here, but no heroes. Stearns resists the compulsion (he is quite open that his editors pushed this way) to come up with a one-true-theory of the conflict and instead attempts – and largely succeeds – to present it in all of its manifest complexity and horror. I should note, however, that this book is a depressing, distrubing read. There are no heroes, but there are many villains and far, far more victims (many of whom are also villains); Stearns does not shy away from the mass murder, brutality, sexual violence and general horror of the conflict. He is not there to spare your feelings, so this might be a book left to read at a time when you are not feeling particularly emotionally or mentally fragile (as opposed to my stupid self that read it in the opening weeks of a pandemic while the job market in my field came to a screeching sudden stop – that was less than wise. Don’t do that.)

Next week: I hope to have the first “How Did They Make It” essay ready, though time will tell if that plan survives contact with my schedule. In any case, next week or the week after, we’re starting with farmers and farming.

160 thoughts on “Fireside Friday: July 17th, 2020

  1. Your blog appears to be quite fascinating! I’d heard the same information about the futile and often counterproductive nature of strategic bombing from other sources, such as John Kenneth Galbraith’s work on USSBS (The United States Strategic Bombing Survey, post WW2), and it all does add up quite well. Part of the issue is the political connection between war, politicians and civilians. In World War Two, civilians were only aware of massive casualties as abstractions in a newspaper and perhaps in a few cinema reels weeks after a major battle. In Vietnam, there was a 2-3 day gap between something happening and the casualties being seen on TV, which set up a wholly more visceral feel to it. With Iraq, it’s pretty easy to see something happen live, from on site. “War as adventure” seems fun to a distant civilian population until they see the horror that it truly is.

    While we’re on the track of science fiction bombardment, I’ve noticed that the science fiction idea of orbital bombardment conflates multiple different objectives. SF writers used to the idea of nuclear mutually assured destruction can’t tell between what an actual invasion would be versus destroying an enemy planet, and it seems easier to turn the surface of an enemy planet to glass like the Covenant do so often in the Halo series, or Moff Tarkin blowing up Alderaan with the Death Star in Star Wars (one as religiously-motivated xenophobia, the other as an act of mass murder meant to terrify dissident populations into compliance).

    The Halo universe seems to actually pay attention to the weakness of strategic bombing. The Covenant are beaten in ground battle even with vastly superior firepower in space or the atmosphere, and even in instances where the surfaces of human planets have mostly been glassed, there are human survivors underground or in fortified locations, so in these cases a level of destruction a whole magnitude greater than strategic nuclear weapons fails to completely remove defenders.

    1. Just a nitpick:

      “Moff Tarkin blowing up Alderaan with the Death Star in Star Wars [..] as an act of mass murder meant to terrify dissident populations into compliance”

      If I remember correctly, Tarkin’s plan was to terrorize the regional governors, who were going to replace the late Senate as the sole manifestations of Imperial authority throughout the galaxy. The superweapon would ensure the governors stay loyal – and the governors would presumably keep the population in check. This matters because, as Brett notes and I tend to agree, the rulers are more easily cowed. Might have actually worked.

      1. No, that’s not quite it. Tarkin, as a Moff, *is* one of the regional governors.

        If you listen closely to the briefing scene (https://www.youtube.com/watch?v=YnNSnJbjdws) fear is keeping the “local systems” in line, not the regional governors (who are the emperor’s personal appointees and loyal to him). So the Death Star is going to terrorize local planetary governments, which themselves run the full range of government forms.

        It’s actually quite a lot like the Roman system: a central power (in Rome, Senate + emperor) which appoints (Roman) military commanders to administer conquered territories, with local governments providing the intermediate step between those Roman commanders and the actual local populace. As in almost all cases, local elites are the necessary core of any rebellion, so keeping those local governments, stocked with local elites, loyal generally locks in the loyalty of the province. I actually touched a bit on this structure in a recent bit for Foreign Policy: https://foreignpolicy.com/2020/07/20/romans-violence-power-police-military/

      2. @Bret

        Ok, that makes much more sense. The local elites, whatever they may be, govern locally, and a centrally-appointed governor links them to the Emperor. So, in this light, would you say the Death Star would have been, on the whole, effective in discouraging the local elites from rebelling?

        Also, the FP article is very interesting. Two things I don’t really agree with, though:

        I’m not sure about the complete opposition and mutual exclusion of (soft-) power and (hard-) violence (or threat thereof) as tools of statecraft. It would seem to me, each has its role. It’s true that soft power is “nicer”, and it’s best when everyone follows the rules because they believe in them. However, rules won’t last long without *some* force backing them up. It’s simply too advantageous to be the one individual that doesn’t follow the rules, when everyone else does – and so, soon enough, nobody does.

        My second objection concerns the Romans’ alleged absence of the use force in relation to the conquered locals. It sounds to me more like an outsourcing of the use of force. They didn’t police the locals, they let the locals police themselves. It’s unlikely that suddenly, crime stopped happening in conquered provinces. People did bad things (by the local ethical standards) and were punished for it. The Romans just washed their hands ™ of it. Which is sensible, as long as they didn’t care how the local communities worked and what they punished people for. This sounds different from the system in the modern-day US, where (if I understand it correctly, since I don’t live there) everyone is a citizen and has to follow the same, centrally imposed rules.

        Anyway, very interesting stuff, there and here.

  2. First 🙂

    Anyways nice post as always. But it begs the question: What if I don’t care for the society and only want them to go away (read die)? If I look at a modern high-tech society (I’ll always subconsciously replace that with Germany, but I think it holds for a lot of the western world), then it looks very fragile. Just bombing all central control hubs (state offices, police stations, logistic centres), whose positions are readily available both on google maps, but also by just tracking the large trucks, would quickly degrade our ability to survive. I think the amount of food in personal pantries is thought to be less than two weeks. Ie two weeks after destroying the logistics the local population would begin to starve and after 2-3 months the problem would be much more manageable.

    If I’m a space faring society, I would expect to have enough technology to do the extraction of resources myself with very little in terms of actual population need. So here comes my question: In how far did the calculus change in the past from: Population + land as an objective to land to just very narrow local patches of the land? Naively I would expect such a reduction in scope.

    1. “I would expect to have enough technology to do the extraction of resources myself with very little in terms of actual population need”

      Yes,but that doesn’t mean you want to. The west has enough technology and a large enough economic base to produce most consumer goods themselves. Yet, look around your house and see just how much stuff you have that say “made in China” (or similar).

      In economics there’s a very important concept called “comparative advnantage”. It is your relative advantage of doing one thing over another, relative to someone else. Which is to say that even if you’re much better at doing both A and B than your friend, seeing as your friend is less crappy at doing B, you’ll leave that to him and concentrate on A yourself – which is your speciality anyway.

      Why is this relevant? Well, firstly because even with fantastical space-tech its likely expensive ferrying all sorts of infrastructure for extracting resources across space (or the means to build such infrastructure in place). That in itself suggests using infrastructure already in place. Furthermore, of someone is already successfully extracting resources from the planet, that suggests they have been able to figure out how to deal with any local pecularities that impact on resource extraction. This is actually a real big one – the number of enterprises that fail on earth due to the lack of local adaptations is staggering, and we can only assume most other planets than earth would be more alien to us than some other place on earth!

      1. Ah, the local population may be a positive hindrance, not an advantage. Such are the complications.

      2. > This is actually a real big one – the number of enterprises that fail on earth due to the lack of local adaptations is staggering

        I always like the story of Walmart failing in Germany because (how surprising) German culture is different from American in expectations.

    2. Okay, but why do you want the planet, then? It’s hard to think of anything, even including habitable land, that you can’t get much more cheaply from asteroids and comets, at least if we’re talking about a society that can control the energy required for semi-routine interstellar transport.

      1. The difference is available mass of resources. Astroids are tiny in comparison. Something like half the mass of the solar system is in the sun, half of the rest is Jupiter, but most of that is hydrogen. If you want heavier elements then you basically only find these in the rocky inner planets. I don’t remember the exact numbers from my astronomy course, but wikipedia says the _total_ mass of the astroid belt between the rocky planets and the gas planets is estimated to be 18% of the moon and the much more extended Kupier belt is estimated to have roughly one moon mass total (1% of the earth).

        Moving to a different solar system requires an investment in both time and resources that is significant (unless we believe that our current understanding of physics is fundamentally broken). At that point I’d be hard pressed to see that the minor pickings of the astroids would be sufficient from a robbing point of view.
        Fundamentally there are only like three resources in the universe: Hydrogen, radiation and metals (everything more heavy than helium, yeah astronomers are somewhat simplifying in their view of the universe). If it’s one of the former two someone comes to this solar system for, then we could in principle coexist, but that would require the other party to trust (or dismiss) us enough that we couldn’t possibly be a threat, otherwise throwing a couple of rocks is just saver. If it’s the latter they need to move past us to get to the resource extraction phase (assuming they don’t need manual labor), so we would just be in the way. Either way, having aliens find us and look at earth in terms of “oh nice resources” is probably ending _very_ badly for us

        1. Yeah, okay, but…

          Let’s say a more teched-up version of us is the invaders. Why would we cross interstellar space for metals instead of just mining or totally taking apart Ceres and Mercury? Or… we’re so resource-hungry that we’ve already dismantled them and maybe Venus, and teched-up enough to cross interstellar space in some reasonable and economic time-frame, but we can’t manage industrial scale transmutation? That seems an unlikely combination to me.

        2. The mass of the asteroid belt (or the various comets and trojans) may be small, but they are far more accessible – you can’t mine that deep on Earth without real problems from heat and rock plasticity. Plus you don’t have to drag your materials out of a gravity well.

        3. The numbers I’ve seen have the Sun be over 99% of the mass of the Solar System, with Jupiter being about 90% of remainder.

          Unless the planets are broken up, most of the valuable metals are tied up in the core. With asteroids, they’re right out in the open.

    3. “Go away” was the motivation for what might be the original example in science fiction, the Loonies (Lunar inhabitants) in Robert Heinlen’s “The Moon is a Harsh Mistress” dropping rocks onto Earth to gain independence. And it was graduated, starting with demonstration strikes and then escalating, “we have a lot of rocks we can drop on your cities. Do you really care that much about controlling us?”

      More recent example is the Belter faction in The Expanse who are quite happy to try for an extinction level asteroid strike on Earth but don’t follow up with an invasion. They figure that a massively weakened and depopulated Earth won’t be able to exploit them any more.

      1. “They figure that a massively weakened and depopulated Earth won’t be able to exploit them any more.”

        Oh my! They will be showed how wrong they are in season 6. Basically somebody becoming the biggest monster in town will make everybody rally behind the former biggest monster no matter how monstrous.

    4. Some complicating factors in this analysis (“we don’t need the people so we don’t mind killing them all, we’ll just blow the hell out of the place and then move in our own colonists and infrastructure”):

      1) It is generally much more time-consuming to build new infrastructure from scratch, especially if one is shipping in the labor force from far away, and *especially* if one has to find a way to motivate the new labor force to come to a barren and devastated world.

      2) If one is fighting purely for resources, in the vastness of space there are likely to be other, more attractive ways to get the resources. Minerals can be found on barren rockballs, and energy is abundant in space even if we assume hard-SF technology.

      3) A would-be star conqueror who actually bothers to attack other people’s settlements almost certainly has a reason to target them. This is likely to include either control of the population (because flipping population to your side can strengthen you) or at least control of habitable environments for your own population to expand into. Either way, wrecking the place you’re hoping to colonize is counterproductive.

      4) Furthermore, many wars will be fought in situations where one side or both is *definitely* hoping to ensure that the territory being fought over survives. Rebels seeking independence from the Empire don’t want to wreck their own homes. Imperials seeking to crush the rebels [i]usually[/i] want to disperse the uprising with a minimum of bloodshed so the province can go back to paying its taxes on schedule.

  3. Since I know for a fact you’re a Shattered Sword fan, I can’t help but think of how aircraft carriers of all sorts (whether Nimitz-class carriers or Wasp-class amphibious assault ships) are still so incredibly vulnerable to fire after all these years. That the Bonhomme Richard may possibly be stricken from the navy list even though it suffered only a fraction of the damage caused on the USS Franklin or the four Japanese carriers at Midway is pretty sobering to think of. 🙁

    1. Though note that USS Franklin wasn’t returned to service either. But in wartime time can be more valuable than money, so if rebuilding a useful warship is faster than building a replacement then that’ll be done even when it actually costs more than a replacement would. It can be worth almost any cost of have a ship back in 9 months rather than a replacement in a few years.

      But during peacetime you can have less time pressure and look at long term cost effectiveness. Compare repair costs to remaining value, and see whether it instead makes sense to total the ship and instead build a replacement. You’ll likely be without a ship for a longer, but at the end you’ll have a brand new ship (hopefully build for the current requirements) with its entire operational life ahead of it instead of, in the case of Bonhomme Richard, a 22 year old ship with about half it’s operational life used up; which is probably going to have some lingering issues from the fire and repair.

      1. Compare road construction projects which run for years, but when something like a bridge collapse on a vital route happens, they have a new one up in a few months. If you need it NOW, you can get it done much faster, for a lot more money.

        Or as they say: Good. Fast. Cheap. Pick two.

        1. When the Mianus River bridge collapsed a few years ago (bridges are fatigue loaded structures, so their lives were drastically shortened by the increase in truck weights authorized during the Reagan administration), it took a few weeks to get a temporary (Bailey) bridge up. Of course, part of that time was spent inspecting the other spans to make sure that they wouldn’t collapse over the next couple of days.

  4. For a broader discussion of alien invasion scenarios other than “slightly more advanced tech than now”, I recommend We Will Destroy Your Planet: An Alien’s Guide to Conquering the Earth by David McIntee, published by Osprey. Not deadly serious, does cover a very wide range of possibilities drawn from the many decades of science fiction literature and on screen.

  5. I’m pretty sure I remember Iraqi tank battalions surrendering to pure aerial bombardment. That’s the military, but if the military surrenders, the government won’t be far behind.

    After that, it’s an occupation, and you need to establish either control points or legitimacy faster than the guerrilla resistance can organize. In which case you’ll probably have a much easier time of it if you *didn’t* kill a lot of civilians on the way in.

    Speaking of civilian targets, another reason not to use mass drivers against cities (or possibly at all) is that it might offend formerly neutral powers. Like when Syria used chemical weapons, but much, much more.

    1. The Iraqi military was almost uniquely ill-suited to survive going up against an enemy with air supremacy. Command and control were very centralized, troop morale was low, and the terrain was so open that there was very little real shelter against air attack.

      So it was a relatively simple matter to blow up the handful of command bunkers through which decision-making flowed, shatter the morale of the troops, and leave them in a position where all they could do was abandon their vehicles and try to give up.

      A military more motivated to fight in defense of the regime, or with terrain that makes it harder to just casually pound the life out of entire map grid squares because the war isn’t being fought in the middle of a huge desert, would tend to perform better.

  6. When you write:

    “Note, 2,000-pound bomb here refers to total weight, not the explosive weight. I don’t know what bombs were used here, but the Mark 84 is a decent candidate, in which case the yield of all five of them would have been around 6,378 tons of TNT (5 bombs each with 945lbs of Comp-H6, which is c. 1.35x the explosive power of TNT), or 6.3 kilotons”

    there is an error in your units.

    5 x 945 lbs x 1.35 = 6378 POUNDS of TNT or 3.189 Tons

    1. Putting our host in the august company of Flanders and Swann, who equated 20 tons of TNT to 20 thousand pounds of killing.

  7. *Hype for the textile production future post*
    I wanted to read more about textile since you’ve touched on it when talking about Sparta. Can you recommend any good materials about the subject while we’re waiting?

    1. I recently read a good book on textiles.
      “The Golden Thread, how fabric changed history” by Kassia St Clair. ISBN 978 1 473 65905 6
      Good overview of all textiles rather than a technical how to.

    2. Women’s Work: The First 20,000 Years: Women, Cloth, and Society in Early Times by Elizabeth Wayland Barber

  8. For an “eye opener” on the topic of firepower and tactical psychology I recommend “Brains and Bullets”/”War Games” by “Leo Murray”.

  9. I remember seeing front-line footage of US and ARVN troops trying to break through to An Loc in 1968. VC and NVA dug in around the only road. Skyraiders, artillery, mortars drench the area with fire; troops run forward, meet fire, retreat; another drenching, same result. You would have sworn nothing could live in that inferno, yet they did.

    What if the planetary invaders truly want just the land? With maybe some infrastructure, but most will be useless to them as it is built for local humans? In other words, the American West – land wanted, natives not. Chem/bio warfare, plus enough explosives to disrupt food production and supply would seem the way to go.

    1. Now we’re getting into the “bigger strategic picture” questions. What actually is the overall distribution and accessibility of earth-like planets in the context? What is the time-frame of the war planners?

      If planets are rare and time-frames are long, then it might make sense to obliterate ecosystems as part of a conquer-by-terraforming program. Aka, pursue a program of genocide, as the United States did with the Native Americans. (Worth noting though that even that involved quite a lot of “foot soldiers.”)

      On the other hand, if mere land is relatively common, then the capital improvements on it, the human society that supports them, will be so vastly more valuable that razing them would be entirely counterproductive. You want a tech base that can produce the semiconductors that run your warships, and that tech base is so large and complicated that it occupies entire societies. Blowing that up would be like killing the golden goose.

      1. Alternatively, we can imagine wars in which planets are not themselves the strategic objective, but (say) control of space routes (if that’s a thing in-setting), or asteroid fields, or gas giants, or w/e. In that case, we might see something more like island-hopping: destroy the planet’s capacity to project force into space, then don’t bother with anything further, because it’s irrelevant to your strategic objectives.

        1. The Humankind Empire Abh would like to assure you fellow humans that they don’t give a damn what you do on your surface, as long as you let them set up a recruiting post, and don’t try to violate their monopoly on interstellar trade.

      2. Yes this. It might be that planets with suitable gravity and temperature are worth it to turn the whole thing into a hellscape.

        1. That makes no sense. If you are so desperate for habitable “land” that you would go thru de energy expenditure involved in having enough firepower to obliterate an ecosystem, moving said firepower to said ecosystem,using said firepower and then going thru the whole energy intensive process of recreating and populating said ecosystem and are technologically advanced to afford all that energy expenditure, wouldn’t it be a more sound investment to build a Megahabitat like a Halo Instalation?,

  10. Hey, i think this post actually makes the assumption that the infrastructure and populace are still needed.
    It is entirely possible that planets would be seen as inferior to custom artificial habitats i.e. Oneill cylinders and offer only a millionth of the living space.
    Though then that suggests planetary invasion isn’t really what you’d be doing but instead boarding cylinders in planet hopping campaigns.

    1. But why even bother with the planet then? What’s the big point?

      The key assumption being made is not so much that you need infrastructure and populace, but that you’re invading the planet for its resources. Needing infrastructure and population simply follows from that strategic goal. As I noted in a comment above, there are reasons to believe there’s a comparative advantage to letting the infrastructure and population in place extract the resources for you, as opposed to annihilating it and building your own.

      1. > Needing infrastructure and population simply follows from that strategic goal.

        No it doesn’t. It only does if you require the local infrastructure and population to extract said resources. If you bring your mining equipment with you then both are arguably only a liability, even if you can actually use/communicate with them. The discussion becomes somewhat more involved if we are talking about humans in x-hundred years and multiple planets raiding each other, then Bret is most likely correct. For alien-human interactions I would not bet on them having any use for us.

        1. But then you’re assuming it’s better to bring your own mining equipment.

          Let’s actually ponder that for a moment.

          So what we’re looking at is extracting resources, yes? And for extracting resources from that planet to be worthwhile we would not only extract more resources than we spend setting up shop so to speak, but also to account for the opportunity cost. That is, whether we could make the same effort to obtain the same or more resources from some other source.

          Now, out of all the countless places in the universe, we’ve decided on this particular planet. It’s just someone else is there already. And we are assuming they are uncooperative, so we can’t simply set up some mutually beneficial interstellar trade agreement. Hence the need for some sort of military involvement.

          So before we’ve even started extracting resources we’re consuming a lot of resources on the military campaign.

          Our endeavour is heavily in the red already, but I’m sure we can appease our investors.

          Then we have the immense logistical task of transporting our own mining equipment to the planet. This equipment must be scaled to be able to extract resources to recuperate our military spending. Which means it’s expensive to move. Which means it also must be scaled to extract resources for that. We’re starting to look at a lot of hardware.

          Then we need some operators. Perhaps most of the operation can be conducted by robots and AI? I mean, we’ve got the technology for interstellar travel, so it’s not a farfetched assumption. Such an assumption would help a lot though, because it means we don’t have to add moving in a human population with all its overhead – you know, housing, food, clothes, various other amenities. It’s simple enough setting up a basic mining village in Nowhere, Earth, but this is a different planet, remember. If we go with the robots we just have to ensure there’s enough energy and spare parts.

          Either way, that’s going to eat into the surplus resources we actually get off the planet.

          At this point our investors are questioning why we bothered with this exact planet. There’s some other planet two lightyears in the other direction with most of the same resources, which is uninhabited. Perhaps our chosen planet is more resource rich and it will all pay off over the endeavour’s lifetime, but with that other planet we wouldn’t need any of the initial waste on military spending. Our investors are patient, but they do prefer their money back within ten years, not within fifty.

          So what was it about our chosen planet that made us prefer it over the alternative? More resource rich, yes. What else was different? An existing economic base and infrastructure for resource extraction.

          During the next meeting with the board a question is put to you:

          “Wouldn’t it have been more simple to make the existing population extract the resources for us, rather than destroying their infrastructure and building our own?”

          You anticipated this, of course. “No, they were uncooperative. We couldn’t simply make a trade-deal.”

          “Sure,” the reply sounds, “but if we have the capability of destroying their civilisation outright, do we not also have the capability to put some boots on the ground and coerce them instead? The robot union is demanding more and more, and I’m not sure the aliens would be worse dealing with.”

          It could be you are quite right, and the board member is a moron. Actually, let’s say he is a moron! In the fictional scenario we’re dealing with, interstellar transportation is dirt cheap and massive mining operations can be zapped right onto a planet at a miniscule cost. Meanwhile, the planet’s inhabitants are as hungry for blood as a swarm of mosquitoes on a damp summer night. You’ve explained this to the board repeatedly. It’s just that the moron doesn’t really understand the possibilities of modern zapping technology. So how do you convince him that it’s better to annihilate the economic base of a planet – including both its physical infrastructure, but also its labour force and accumulated knowledge, including knowledge of the local, planetary conditions – than finding ways to exploit it?

          How do you ensure that when he sees the civilisation down on that planet he doesn’t get dollar signs in his eyes, but instead want to press the red button?

  11. If the aliens mainly view earth as potential competitor, they may be content to blast the Earth into a sufficiently low technological level. Or blow the planet to pieces.

    On the other hand, they might consider themselves obliged to convert all intelligent life to their religious and/or political worldview, in which case they would probably need much more complicated forces compared to mere extraction of economic resources.

  12. Hitler’s generals figured out that you can replace some firepower with time. Instead of bombing Leningrad in a sort of Blitz, they just surrounded it and let it hunger. Indeed, it did not diminish the morale of the people of Leningrad (well, for the most of them – some reverted to cannibalism and other horrible things), but had the blockade lasted a bit longer, there would have no able-bodied people left to fight.

      1. Is it really ‘striking’? Given that iirc the Germans never actually managed to stop the flow of supplies into Leningrad it doesn’t seem all that unsurprising that the city held until the Red Army was able to finally force back Army Group North and break the siege. Note this isn’t trying to overlook or dismiss the shocking suffering the populace of Leningrad experienced or the efforts and heroics involved in getting the supplies that did make it into the city there (both of which were incredible). But given the failure by the Germans to actually cut off the city, the ultimate failure of the siege would seem like the most likely outcome (or at least, the fate of the siege would be dictated by the outcome of the wider war).

  13. The weapon you really need to worry about in extreme Science Fiction scenarios is time-travel.
    Which I suppose could be viewed as a form of invasion, albeit at a point at which planetary defenders may be completely incapable of effectively resisting.

  14. For the sci-fi stuff it raises the question of if the space facing polity would WANT to control the planet in the first place. Seems like it’d be easier to just crush whatever spaced based forces the locals have an establish a monopoly on insterstellae trade and get whatever you want that way without having to get your hands dirty administering the planet.

    For the making stuff part I’ve read up a lot on pre-modern brewing and it continues to astound me what deeply different ways they want about really basic things.

    A good example is this truly excellent blog: http://www.garshol.priv.no/blog/

    The author travels around rural Scandinavia/Baltic/Russian areas and meets up with farmhouse brewers and tells about the processes they use to make their beer. Many of which fly in the face of modern homebrewing conventional wisdom and so things that we’ve been told would make undrinkable slop and then the tells us how good the beer is and how different from anything commercial.

    He’s singlehandedly injected a bunch of “new” techniques into the homebrewing community (especially the use of Norwegian yeast which for bizarre reasons thrives and makes good beer at warm temps vastly better than anything else, and in general is just incredible) that are slowly percolating into commercial brewing.

    Also the sheer diversity of techniques he’s used is just astonishing.

  15. “No civilian populace (note: not military junta or dictator) has ever been persuaded to give up on a war effort because of aerial bombardment in the absence of political pressure or ground operations.”

    Interestingly though, it _has_ happened with naval bombardments, such as in the Zanzibar War or the Opening of Japan. It probably wouldn’t have worked in a life-or-death struggle, but in these limited situations, Gunboat Diplomacy did do its job. So that might be another angle in a Science Fiction story – you turn up with your fleet and demand limited terms, which then might well be met once you own the space around the planet.

    1. And then there’s the nuking of Japan, of course, but that would in every likelihood not have been enough had the war not already been functionally won already by conventional forces. It could be a model for an SF situation though. You have crushed the opposing fleets and their defence installiotions, destroyed all the infrastructure, and thrown rocks on a few cities – this is the point where unconditional surrender might well happen, presuming you won’t get eaten afterwards, or something like that (which is another reason surrender might not happen – the terms would be intolerable if you’re going to be food, parasite hosts or breeding stock).

    2. John Ringo’s Troy Rising has a race of space pirates that use this MO, more or less. They drop a couple of asteroids on the most populated cities, then say “Pay us X tons of precious metals, or we drop more asteroids.”

      If you have firepower that’s orders of magnitude beyond your opponents, and if you’re trying to extract terms from a civilian population that isn’t keen on spending the next several years living in caves fighting a guerilla war, then you can probably get fairly substantial concessions without needing a ground invasion.

      1. Of course, they still *lost* in the end, because without boots on the ground they had no way to control the specialist populations they needed to, and couldn’t effectively punish them without destroying the resources they wanted.

      2. Wait. I have access to asteroids, and I can move them more-or-less at will. Why am I wasting my time with the dirtsiders?

        It’s a very specific level of.. laziness? that deems it easier to extort dirtlings by dropping rocks on them (and apparently backing that up with a ground invasion?) than it is to grab a hefty chunk of something like 16 Psyche.

        1. Moving rocks around does not give the same rush as moving people around as if they were chess pieces.

    3. The problem is that in both the Zanzibar War and the Opening of Japan, the special caveat Dr. Devereaux introduced applies:

      “No civilian populace (note: NOT MILITARY JUNTA OR DICTATOR) has ever been persuaded to give up on a war effort because of aerial bombardment in the absence of political pressure or ground operations.”

      The Zanzibar War was a straightforward matter of replacing one dictator (dignified by the name of monarch) with another. This was easy enough for the British, given that the dictator’s palace was within artillery range of the harbor. Something similar applied in the Opening of Japan, where the shogunate did not ultimately survive the intrusion of outsiders. Not when the outsiders’ artillery could force the leadership, *personally,* to engage with foreigners under threat of being personally obliterated by gunfire.

      Now, the one advantage of orbital firepower over warfare on and near planetary surfaces is that one can directly target enemy leaders almost at will. Unless the enemy leaders live in a bunker so fortified that even orbital bombardment cannot destroy it, you are always in a position to compel their surrender by blowing up *them, personally.*

      However, this only works if you’re prepared to pursue the kind of strategy consistent with ruling over a wide empire by intimidating local elites. Namely, a fairly decentralized one.

      1. You also have to know where the leader *is*.

        There’s also whether you can safely stay in orbit; after all, you’re at least as exposed as anyone on the surface. Material attacks have to go by rocket rather than just falling, but lasers won’t care which way they go.

        Bombardment by anything smaller than Really Big Rocks is potentially deflectable by defenses. Really Big Rocks have their own energy costs and lack of precision.

  16. I’m not sure that drawing so heavily on WWI and WWII comparisons is correct here. Back then, the big problem was getting a weapon where it needed to be, and tremendous strides have been made in that area in the last 50 years. These days, for a couple of thousand dollars, we can slap a guidance kit on a bomb which will get it close enough to destroy whatever it’s aimed at. It’s no longer “how many sorties do we need to destroy this target”, it’s “how many targets can we destroy with this sortie”. I don’t see any reason to assume that a hypothetical space invader won’t have the same or better capabilities. (Lasers in particular offer the next step up in terms of precision firepower delivered on very short notice.) So I don’t think it’s reasonable to assume that a planet’s defenses will be able to put serious mechanized/industrial forces in the field to oppose an invasion. Particularly when their infrastructure is also vulnerable to strikes on whatever node is hard to repair covertly but cheap to replace when you don’t have someone dropping tungsten rods on you.

    Of course, defeating those kind of forces is only half of the problem, and in a lot of ways the easier half. That’s something you’re a lot more familiar with than me.

    1. Second Gulf War, though? You can dramatically soften up your enemy using air power, and ruin all his command & control and infrastructure, but if he still wants to fight after that, you’re out of aerial options. The ground invasion will be much easier now, but you will still have to perform it.

      1. I don’t disagree, and 2003 was exactly the model I was thinking about for this. But being able to reduce your enemy to an immobile insurgent/infantry force is a huge win for the invader, and we shouldn’t lose sight of that.

        1. If you dig into the US/Coalition air-campaigns in 1991 and 2003 though, the airpower alone thesis begins to break down. You find that ‘sorties redirected’ numbers spike early and stay high, indicating planes being redirected on targets by ground forces during the crucial days. It wasn’t strategic airpower that was decisive but close air support.

          Of course, to do close air support requires something to be closely supporting (from the air) – which is exactly the point I make about needing a ground force to enable target acquisition and selection. That problem has remained true even to the present; Biddle discusses it in his article.

  17. Interesting. As a newly winged Harrier pilot in 2011, my son was discussing with me this point: “strategic airpower advocates have long been promising that aerial firepower (in the form of bombing) would render ground combat obsolete precisely because the sheer firepower or the threat of firepower would force the enemy to surrender,” with us both coming to the wrong conclusion. Because he wanted to fly, fly and nothing but FLY, the idea disappointed him at the time. I see now that we were both under-supplied with the facts.

    Meanwhile, Bret, a couple proofreading corrections that could be made:
    point is to consider is what -> point to consider is what (delete first instance of is)
    destroyed, it a logistics -> destroyed, be it a logistics

    1. This a bit like Cherryh’s Alliance/Union universe after *Downbelow Station*. The Earth Fleet had been undersupplied to begin with, raiding merchants for supply, and then is forced to go full rogue, as the Mazianni. You don’t get that much of the campaign against them though, they’re more of a lurking or climactic threat.

      I do wonder how they manage to keep fueling themselves, but Cherryh’s vague on what fuel is anyway…

      1. It seemed clear to me that fuel* was water. Miners in the outer system mine ice from moons or comets, refineries process it, and “skimmers” transport it to the main station. It is noted that without high speed pumps it can take days to fuel a ship.

        A central plot element of Rimrunners is making sure the Mazianni carrier they are stalking doesn’t get the big supply of water from Thule.

        * Or perhaps reaction mass, to get picky.

  18. I had an idea for a Star Wars campaign immediately after the Empire collapses. Because of hyperdrive Imperial capital ships aren’t designed to operate autonomously for extended periods. They would warp to a system, fight, then warp back to a home base to re-provision (including food). When the Empire collapses, they no longer have home bases to return to so they are forced to extort resources from planets. The players would be rebels on the planet trying to destroy the orbiting Star Destroyers. As you point out the Star Destroyers can’t simple lay waste to the planet because it needs the resources to keep operating. The campaign would involve many theaters: ground assaults and guerrilla tactics, aerial combat in the atmosphere against TIE fighters, orbital X-Wing assaults against the Star Destroyers and covert missions into the Star Destroyers.

    1. Extort? One option. Another is to haggle. They are useful in the chaos, no doubt.

      Depends on personality and circumstance, of course.

    2. That sounds real interesting.
      The jack-of-all-trades nature of a Star Destroyer makes it uniquely suitable for living off the land.

  19. You can bomb it, fry it, douse it in chemicals and roll over it with a tank, but you don’t own it until a 19 year old with a rifle is standing on it.

  20. In the forums and subreddit for the Paradox Interactive sci-fi game Stellaris, I’ve often seen people expressing ideas similar to Spacedock’s video, that the overwhelming firepower of spaceships would render ground troops obsolete. Even Wiz, the game’s lead developer for a while, expressed similar sentiments while mulling over how to change the planetary invasion mechanic and whether or not to remove it entirely (it never got removed or changed significantly in the four years since its release, though with how much Paradox changes their games, it’s a matter of WHEN it gets changed and not IF).

    Funnily enough, the way that planetary invasions work in Stellaris follows pretty much the exact same logic Bret laid out in this article; you NEED to send in ground troops in order to actually occupy a planet. Bombarding it with your fleet makes it easier for your troops to do the fighting, but you can never fully capture a planet without sending in the boots. And bombarding the planet is risky too, because doing that too hard or for too long will kill civilians on the planet and destroy infrastructure. There’s also a devastation mechanic which causes all sorts of problems for production on the planet, and it can persist for years in-game after the fighting on and around the planet finishes.

    1. However, you don’t need to invade if your goal is to simply exterminate the population (say, because you’re playing Fanatic Purifiers, or because you’re fighting the Scourge).

      That said, Stellaris invasions are generally pretty easy. Defensive armies will almost always be weaker and less numerous than assault armies (because you can ship in as many assault armies as the empire can afford, while defensive armies are limited to what a single planet can support), and even selective bombardment will move the armies from “troublesome” to “speedbump” with a little patience.

      Basically, if you can park a fleet in orbit, the planet is yours, bar a few months waiting for the invasion fleet to arrive. You’re never going to have a Cadia scenario where failing at ground warfare brings the invasion to a halt – at best you make the enemy spend a few extra months softening the planet up.

      1. You can do your own Cadias with the Scourge if you can’t fight them back this instant (meme build, high crisis multiplier, etc).
        Block the chokepoints to your territory with habitats with a lot of fortresses (for the inhibition), stuff them with pops and you’ve got quite a lot of time while they try to chew through.
        This is borderline exploit though.

      2. Honestly the missing piece in most of these games (stellaris, endless space) is the missing ability for the planet itself to shoot back. That’s the thing I don’t really get – you think about almost any weapon you could conceivably mount on a ship, and you have to ask – why can’t you build that gun on a planet? Same with shields, same with everything else. It seems to me that the only way a planetship battle wouldn’t be massively in favor of the firepower of the planet is if you have a ship (c.f. death star) that literally is so big it’s pretty much a planet itself.

        You can make all sorts of hand-wave arguments “well, the ships have energy shields” … but yeah, why can’t the planet have localized shields (like the ones in Empire Strikes Back)? You run through almost everything, and it seems to boil down to really one advantage the ships can do that you arguably can’t do with a planet without destroying it’s habitability as a planet (or getting into such insanely high-tech-levels that we’re no longer operating in the realm of ‘space opera’ fleets): you can’t move the planet. Planets are stuck in their orbit. Ships can move around. Ships are in great danger within range of the planet’s guns, but they can do whatever they want, with impunity, outside of it.

        If I were doing the design of these games, ships could totally seize control of the rest of a system, blockading all the star lanes, etc, but they could never get close enough to bombard the planet – not without willfully taking a lot of retaliatory abuse, which hopefully would be tuned to be occasionally merited. If you wanted to actually take the planet, you’d have to muster a massive ground invasion, and like a D-Day thing, a lot of those dropships would get taken out on the way to the ground. The key change I’d make is that unlike the existing games out there your fleet would genuinely be able to do nothing to help the ground battle, besides prevent reinforcements. (Another big factor here would be introducing meaningful levels-of-fortification – where fledgling colonies really can be easily invaded because they haven’t build the colossal planet-mounted guns to shoot back. Or where empires have chosen to favor economic development over fortification.)

        I feel like, ironically, the game that did the best treatment of fleetplanet battles was what Sir Meier’s “Pirates!” did when your ships attacked a fort; unlike other seagoing ships where you could beat them with sustained cannon fire, the forts were nearly indestructible, so you basically just wanted to bum rush them as fast as possible to get on even terms in close combat.

        1. I feel like you’re missing something terribly important here… which is ironic because you go out of your way to mention it yourself: You can’t move the planet. Planetary ground-to-space defenses would likely be useful, for psychology if nothing else, but they’re not the automatic win button against spaceships that you’re making them out to be.

          If you’re in a ship and you want to shoot a planet, then all you need to do is some math: just make sure that your shot ends up at the same point in space and time as the planet does, and you’re good. Given that we earthlings already have the ability to land an unmanned spacecraft on an asteroid, it should be routine for advanced galaxy-spanning civilizations to achieve at least that level of accuracy with, say, a missile.

          Compare this to a ship, which if it knows you’re shooting at it, has the ability and incentive to change its velocity. All other things (i.e. questions of shields and so on) being more or less equal, it’s like a dodgeball competition between a dragonfly and the broad side of a barn: the barn is essentially guaranteed to be hit, but also it’s more likely that a given, chosen, dragonfly-sized target on the stationary barn will be hit than it is for the highly mobile dragonfly to be hit.

          And keep in mind that one advantage of space is that you have essentially infinite range! You raised another good point, in that attacking ships aren’t likely to park themselves in low orbit; they’re far more likely to noodle around at long range, launching their projectiles of choice until they feel like enough of the planet’s known ground-to-space defenses have been wiped out. In this light, the odd thing left out of games like Endless Space is not the way it abstracts planetary defenses into modifiers affecting siege attrition rates and ground combat, but rather your inability to build hyperspace-capable weapons that could be launched from one system into another to take advantage of this indefinite range.

          Your Pirates! analogy leaves me a bit puzzled, too: the whole point of a fort is that it’s hard to take, yes, but it’s not like there aren’t any historical examples of forts falling to naval bombardment. Isn’t that part of how New Orleans was taken during the US Civil War?

          1. OTOH if we’re talking real physics then you’re probably greatly overstating spaceship mobility. Delta-vee limitations mean it’s less “dragonfly” and more “train without rails”.

            Planetside, ocean-based defenses (like laser submarines) are mobile and can dive underwater for both shielding and the only true stealth in the fight. They would also benefit from a massive heat sink.

            If we’re not talking real physics then it’s pretty arbitrary. Maybe the planet benefits from shields and superweapons powered by reactors too big and massive to move.

  21. Going to add the orbital bombardment thing to the list of things animorphs got right (and for the right reasons). It’s made clear pretty early on that the yeerks have the technical ability to make Earth uninhabitable at any point, but that would destroy the human resources they want to get, so they’re stuck fighting guerilla forces with ground troops.
    It’s occasionally floated on the yeerk that they could destroy most cities and just take whatever humans are left over, but the more competent vissers shoot this idea down because it wouldn’t make things much easier (lots of humans with small arms left to fight and complicate the resource extraction problem).

  22. Haven’t even read your post yet but immediately after arriving had to compliment you on the excellent fireside picture.

  23. A few general comments:
    ‘…How much firepower do you need to remove deeply entrenched infantry? A lot, it turns out. Stephen Biddle (you may recall him) wrote a piece in Foreign Affairs (82.2, 2003), “Afghanistan and the Future of Warfare” where he laid out some statistics for firepower against entrenched infantry. He noted, for instance that “French defenses at Verdun in 1916 endured a two-day German artillery barrage equal to about 1,200 tons of explosives — in nuclear parlance more than a kiloton, or more explosive power than the w48 tactical nuclear warhead — yet enough of the entrenched defenders survived this maelstrom to halt the German assault [emphasis mine].” And “On July 18, 1944…[the allies] deposited…more than 8 kilotons of firepower — on just seven kilometers of German frontage in less than three hours [emphasis again mine].” In both cases, there were enough defenders left not merely to fight, but to actually win both battles. Nor is this merely a feature of old dumb-bombs; in Afghanistan, Biddle notes, “One dug-in al Qaeda command-post was found surrounded by no fewer than five 2,000-pound bomb craters. Still, its garrison survived and resisted until overrun.” In short, it is possible for infantry – with only improvised field-fortifications – to sustain energy delivery on the level of tactical nuclear yields and not only survive, but be fightable at the other end…’
    That looks like erroneous use of statistics to me. By that style of presentation, I can prove by throwing enough ping pong balls at a watermelon over time that watermelons are immune (by comparison of the cumulative energy to which the watermelon has been subjected to from ping pong balls) not only to direct hits from bullets but to artillery shells.
    As far as I understand (or misunderstand?) these things, aren’t the facts which matter for any physical attack against armour how much energy can be directed and CONCENTRATED AT ONE POINT in one instant? (And in medieval weapons wasn’t that the entire point of ‘warhammer’ style weapons?)

    ‘…Which is just a real howler as students of the Pacific Theater of WWII will be well aware, because this exact situation happened, over and over again – the only eventual outcome did involve an invasion of the island literally every time…’
    Didn’t the United States happen in those cases to need those islands cleared (sometimes for their own use) ‘now. today, immediately’ and didn’t have time to reduce them by prolonged bombardment & siege campaigns?
    Compare with Truk which the United States simply bypassed.

    I will add though that it seems to me that planetary invasions of heavily inhabited worlds ought to be unlikely except in cases of enormous technological and/or weapons superiority on the side of the attackers, simply because absent a magical ‘portal’ or ‘portals’ to an attacker’s home world, their invading armies can simply be overwhelmed by sheer weight of numbers by the defenders (1). Bombard repeatedly from space until they starve and surrender (however long that takes) seems to me to be the way to ‘go’, as with medieval sieges. Literally destroy their infrastructure (and attackers have gravity going for them, for kinetic attacks limited only by the amount of material to hand, if nothing else) until they give in or are literally back in the stone age and can be mopped up by deploying ground forces.

    (1) And planetary inhabitants also have the advantage of knowing the terrain and having had ample opportunity to have hidden things in it. Yes, the Ewoks in ‘Return of the Jedi’ are mostly played for comic effect, but it seems to me that there is half a point there about how bad things can happen to invaders in unfamiliar terrain, even against ‘inferior technology’.

    NB
    What particular version of the element ‘Handwavium’ and background context is in use in the scenario of any given author may significantly affect whether tactics & strategy favour siege or direct assault, it occurs to me. If potential invaders have a warrior-culture which is equipped with super-duper magic swords and requires personal combat if at all possible, then no matter what they can pull out of the hat, technologically speaking, invasions are probably going to be inevitable.
    If potential invaders have limited moral & ethical concerns (as we understand them) and a ‘zorpa-radiation’ (TM) weapon that kills people at a distance (and underground but within half a mile of the planetary surface) from space, why bother putting boots on the ground and risking losses instead of cutting loose with the death-rays if the defenders are foolish enough not to surrender?

  24. Topical to this, but in a less modern context – do you (or anyone else) have any sources to look into when it comes to the subject of converting “Having the biggest/victorious army in the area” into “Actually ruling an area”, in the context of classical or medieval conquest? I remember a mention on this blog that controlling castles does not automatically flip the surrounding kingdom as depicted in games, and was wondering where to start looking if I wanted to think about how to create more interestingly realistic models of this in games and stories.

  25. Forgive me if this is a rankly amateur question, and I feel like the issue has already been touched on a couple of times in the comments, but what about a war between galactic empires where one side was willing to completely raze (the useful infrastructure of) a planet in order to “make an example of it” and convince the leaders of other planets to surrender? Shakespearean monologues aside, was this tactic used much/effectively in premodern warfare?

    1. Genghis Khan, from what I’ve seen mentioned in some places online, may have decided to ‘make an example’ of a country called ‘Khwarezmia’, after they did bad things to a diplomatic mission he sent to them.
      I’m not sure how much real world supporting evidence there is though for the online stories and claims about the events.

      1. Chinggis Khan destroyed the capital, killed a lot of people (estimates as high as a quarter of the population) and deported many others from the Khwarazm Shah (or Khwarezmia, same state). He destroyed the ruling dynasty and aristocracy, but occupied the rest and imposed tribute, so it was not total destruction…but it was quite a lot of destruction.

      2. I remember the “special treatment” of the Khwarizm Shahdom by the Mongols in a few academic history books, so assume there is some documentation for it. But that wasn’t terror on a civilian population to make them surrender. It was a special one-off case because the Shah had broken diplomatic immunity and the Mongols wanted to make it very clear that You Do Not Get Away With This. And given the widespread and long lasting tradition of diplomatic immunity, IIRC even the historians among the opponents of the Mongols generally agreed that yeah, the Khwarism Shad deserved it.

        (A major reason why I hate, hate, hate that scene in the movie LOTR where Aragorn kills the Mouth of Sauron instead of just taking back Frodo’s gear.)

        1. They also gave the same special treatment to Kiev, Baghdad and a couple of places in Afghanistan (I visited one – now called Shahr-i-Golgolat – the City of Skulls). The Mongols definitely thought making an example – or maybe just destroying a possible centre of resistence – was worth it.

    2. I thought “if the city resists and is taken it will deeply regret it” was standard practice throughout history. Assyrians, Crusaders, Mongols, Alexander…

  26. Completely agreed with the analysis on the limited utility of orbital bombardment. Which leads me to another thought: interplanetary war settings typically assume that planets are atomic political units, with world government. But there’s no reason to expect that would necessarily be the case! If control of near-planetary space does not automatically allow one government to militarily dominate others, then it would be plenty feasible for there to be many governments on one rock, or for that matter “star nations” that claim recognized territory on many planets without necessarily dominating any of them.

    1. And indeed this situation could be self-perpetuating—since a planet where, e.g., each continent belongs to a different star nation would be a much less attractive target for glassing and other planet-wide terror tactics.

    2. History of Earth suggests to me that a disunited planet will be easier to take over by a larger power that can establish orbital control, not harder. “Hi government X. If you agree to become our subjects, we will demolish most of your hated enemy government Y for you. You have a week to agree, or then we make the same offer to goverrnment Y.”

      1. “Divide and rule” worked for, among the British in India, the conquistatores in Spanish America, and the various imperialists in Africa. A divided planet would probably be easier to conquer. Find a country with a leader who is resentful of second-class status, support him (most likely) against his nearest enemy, rinse and repeat.

    3. In a rational world that might work, I believe.

      Practically and assuming tech superiority of the invaders, parallels to various superpowers stints in Afghanistan may be not one hundred percent accurate, but relatively close.
      You can pick British Empire, Soviet Union, United States of America, maybe in thirty years China too. A lot of interesting happenings went there.

      Planets are too damn big.

    4. OTOH colony planets might more naturally have single governments, like Australia or New Zealand. And global integration of economy and especially environment might provide pressures for even evolutionary homeworlds to unify. Earth hasn’t gotten there but we’re basically still in diapers as far as high-tech history goes.

  27. Would the threat of orbital bombardment be more effective if the general population isn’t heavily invested in their government, or don’t consider the invaders an existential threat?

    I’m thinking here of the David Weber Honorverse setting, where warfare – at least as far as planetary populations are concerned – is something like medieval Italian city state warfare with condottieri, or 18th century European warfare before mass armies. The fighting is over who gets to be in charge (and therefore get rich) but since all the states are culturally very similar, it doesn’t matter too much to the civilian population. How many are going to willingly endure the hardships of orbital bombardment and invasion?

    1. That’s quite close to McDonald’s peace theory in space.

      I’ll refrain from the cheap mention of the Seven Years War, but I’d like to ask how a general population that isn’t heavily invested in the government can change it quickly enough in order to avoid bombs?
      First it has to somehow find the political power to remove the government, second it has to form something coherent (usually it’s much harder than a revolution, which usually isn’t a piece of cake to begin with) and something it is heavily invested in (quite a shift in the mindset), third it has to be able to negotiate something successfully.

      It seems likely to me that a populace not invested into their government is disenfranchised, voluntarily or no.

      1. I don’t know what “McDonald’s peace theory” is. Can you provide me with more information or references please?

        If the general population isn’t invested in the government, they might have trouble changing it – depends very much on the society in the Honorverse science fiction example – but they won’t fight for it either. If the orbital invaders drop a rock on the parliament/congress/palace, the civilian population and quite likely a good chunk of the armed forces aren’t going to carry on fighting in their name. (Again, assuming that the invaders want to take over, not exterminate.)

        1. “No two countries that have a McDonalds ever went at war with each other.” or something like that.
          Wishful thinking that values and trade trump bombs. A bit like socialists’ expectatation that in WW1 workers will refuse to kill or aid to kill workers on the other side and rather revolt than do so.

          > If the orbital invaders drop a rock on the parliament/congress/palace…
          …a vacuum of power emerges. And nature abhors emptiness. So, this vacuum will be filled, this or that way, mist likely violently, like the air rushing in after a thermobaric explosion.
          There are following broad scenarios:
          1) new ground-based single govt backed by the people emerges quickly
          2) a lot of new ground-based govts backed by various cohorts of the people emerge quickly and after a period of violent (in rarest cases, non-violent) struggle one or two govts remain
          3) an invader-based govt is created and is accepted by the people wholeheartedly
          4) an invader-based govt is created and at least some cohorts of the people are wholeheartedly against it

          Option 3 is the most quiet one and requires a really docile and detached populace that prefers to be the second in Rome than the first in a village.
          Most likely (if we’re talking about humans) are options 2 and 4 (option 2 may be preceded by a short-lived option 1) — the examples are amply peppered throughout the human history.
          Keep in mind you need “just” low single-digit percents of the population willing to kill and die in the name of a cause to get the insurgency (glorious revokution if it succeeds) ball rolling.

          Simply put, if you create a vacuum of power violently, you’re very much guaranteed to have blood on the streets.

  28. I think it’s interesting that you highlighted the nuclear bombing of Japan as being an exception, when there’s a wide variety of interpretations. I’ve tended to lean towards the Russian entry in the war, but the linked article below gives some convincing analysis given the state of affairs at the time. It amounts to 3 basic points:
    1) Japan had already had 68 cities firebombed to oblivion, why would they care about 2 more.
    2) Timing is all off – it took them 3(!) days to meet to discuss surrender after Hiroshima. Seems lengthy if it mattered a lot! And if it was the second bomb…. well that one went off after they already started meeting, so not terribly convincing.
    3) Russia entered the war just after midnight on the 9th. This *definitely* would’ve been known by the time they had the meeting, and it’s thus reasonable to think that the meeting was a consequence of this.

    https://foreignpolicy.com/2013/05/30/the-bomb-didnt-beat-japan-stalin-did/

    1. This exactly. I came to this comment section planning to post that very article and was pleasantly surprised to see someone had already posted it. More historians are coming around to the view that the actual final trigger for Japan’s surrender was not the atomic bombings but the Soviet entry into the war, which frankly makes a lot more sense than the atomic bomb narrative, for the reasons explained in the article.

  29. I feel that people are concentrating on firepower too much, and other concepts too little.

    Increased firepower of itself does nothing to make armies less valuable. All it gives you is more widely dispersed armies. In the 1950s the natural response to nuclear weapons was to have the units more widely spaced so they could not all be caught in the same blast. It was not much of a disadvantage, so long as you had nukes of your own.
    What changed things more radically, was the development of weapons with ranges great enough to strike throughout the enemies homeland, from bases in your own homeland. How can any army protect them now? Only if it can conquer your homeland fast enough to stop you destroying theirs. If you have a few thousand nuclear-armed ICBMs, this seems unlikely.

    Of course, if both sides have thousands of ICBMs, you end up in the position of President Reagan in the 1980s, who is said to have taken part in a war game in which the whole of western civilization, and every thing and person he cared for, was obliterated in a matter of minutes, and the only thing he could do about it was murder a few hundred million people in retaliation, in the sure and certain knowledge that almost none of them had any say in the attack he was retaliating against. Of course, it was only a game. It could have happened for real that evening.
    Still, it could have been worse. At least the other lot knew he could shoot back. Imagine what world politics would have looked like if the only people in the world with nuclear weapons with such range had been the Soviet Strategic Rocket Forces. I think it is safe to say that they would have had something of an advantage in international diplomacy. One they could be deprived of only by similar, countervailing Strategic Rocket Forces.

    This is approaching the position that Spacedock imagines an invaded planet being in, in some space opera setting. I imagine most planetary governments in such a position would be very reluctant to disobey the invader in any way the invader could easily detect and punish. Which puts them somewhere between the position of Cold War Finland and Vichy France. That should be enough for most invaders.

    Actually, any army of the planet would be in a slightly worse position than this suggests. Armies usually defend things by interposing themselves between the things to be defended, and the forces trying the seize them. How would an army marching on the ground interpose itself between the points on the surface it cares about, and outer space? On the face of it, there is no way the army could stand its ground or run, and it would not be that easy to hide. Geometry just does not favour an army confined to two dimensions, against an opponent that can manoeuvre in three.

    It would seem that planets would be defended by a fleet, and perhaps something analogous to coast defence guns. If they fail, it would seem natural to emulate many fortresses after a practicable breach, and start talking to the enemy about “preventing the effusion of blood”. They could choose to emulate the Jews at Masada. But, generally speaking, not many people do so.

    1. You might be surprised
      Basically it depends on whether the defenders believe surrender would be survivable and submission tolerable. If the answers are no then the chances of a Masada or Alamo go up.

      1. I am certain to be surprised, on occasion. But in most cases, given a choice between near-certain death if they don’t surrender, and a promise of life if they do, most people have chosen to bet on the promise. There have been exceptions. Look at Jauhar in India: https://en.wikipedia.org/wiki/Jauhar But that sort of thing was famous precisely because it was, in most parts of the world, rare. Slavery was a thing because most people did NOT prefer death to surrender.

        1. Speaking of India, I remember some pretty grisly cases during the Mutiny when surrender proved to be a fatal mistake. A lot depends on how credible promises of mercy are.

    2. As far as I know the best case for this situation would be Stalin’s USSR position against the “evil” USA at the end of WW2.

      USA had just shown they had nuclear weapon, the will to use them and had for some time the industrial capacity to gain air superiority basicly anywhere they would like. And at taken several order of magnitude less casualty in the war.

      And even then they could not bully him with threat or air firepower because everyone thinked the red army ground force was up to the task.

      So I would think that surrender isn’t the only option against massive air superiority.

      1. Thing was, we actually didn’t have enough nukes on hand to really damage something the size of the Soviet Union, at the time. Stalin knew this.

    3. There are some key assumptions that get made rather casually in this analysis.

      The big one is protracted occupation by orbiting forces that can credibly threaten to kill everyone on the planet for noncompliance. Note that the word “credibly” is doing the heavy lifting there.

      The conditions in which an interplanetary polity’s ability to apply military force to a planet matter are:

      1) Attempt to conquer a non-friendly/uncontrolled planet
      2) Attempts to exercise coercive power against a normally friendly/controlled planet that isn’t being as cooperative as you’d like.

      In case (1), you can roll up with a big fleet and threaten to kill everyone if they don’t bow down to your new government (be it local puppets or imperial administrators- no practical difference). But the big fleet will presumably have to go away eventually, and then you’re back to case (2). Even if that doesn’t happen, if the locals have potential allies with a fleet of their own, they have a strong incentive to stall for time and delay totally surrendering. Firstly because allied fleets might drive you away before you can enforce your will, and secondly because allied fleets who do this might be a tad bit *resentful* if you surrendered too quickly.

      So the inhabitants of the planet face a difficult calculation. How likely are you to snap and kill them all for resisting, actively or passively, versus how likely is it that their resistance will buy them something worth having? Remember that passive resistance is a real issue for an aspiring star conqueror if you’re trying to do anything other than scoop up small amounts of easily portable loot: “we’re trying to gather the tribute but it takes time,” or “milord, our planetary militia is still subduing the last holdouts, I recommend that your administrators and troops remain in their cantonment in the capital for their own safety while we sort out these diehard rebel scum.”

      That segues into case (2): what does your empire to do nominally friendly planets that just aren’t cooperating? Here, the “snap and kill everyone” solution is even less attractive. In the long run, blowing up a planet and rebuilding the population and infrastructure from scratch every time the local governor’s tax collectors start dipping their fingers in the till means you won’t have very many planets left. And the planets you do have will be seriously considering defecting to any major rivals of yours who can promise them basic security.

      Real governments in this situation have to create varying degrees of force to maintain their authority. Local police and militias can secure willing or semi-willing compliance from the population; appointed governors and local elites can actually administer the place. If you don’t have the resources to keep a large bureaucracy in place on the friendly planet, their compliance will always be a bit corrupt, shaky, and unreliable- the tax receipts *will* be underreported, the tribute payments *will* tend to be a little bit late or a little bit light. And trying to enforce this purely with the threat of mass devastation against the target population is a losing game, because then the imperial government has to balance the value of the ‘corrected’ tax receipts against the cost of the punitive expedition plus the opportunity cost of taxes NOT gathered from a devastated world.

      Ancient societies routinely accepted slavery and vassalization as the alternative to death… but ancient societies also usually accepted much lower standards of efficient governance. Because the ONLY way to govern an empire was to farm it out to a bunch of potentates who all had a vested interest in not actually passing the imperial government any more resources than they had to. And the ONLY way the empire had of maintaining compliance was the threat of overwhelming force, which was expensive to mobilize and inflicted costly destruction on the noncompliant province.

      So what were by modern standards very high levels of misrule and noncompliance by provincial rulers tended to be tolerated by imperial governments, as long as the provincial rulers didn’t directly plot against the emperor. The result was states that were big and powerful by the standard of the times, but far weaker than a modern-style nation-state of the same size that is governed by consent of the governed.

  30. Looking at Sci-Fi and planetary invasion/occupation we can look at the 40k universe, which follows the contours of the post. Either lighting raids by elite forces to topple planetary governments and install a puppet government to pay taxes. Otherwise its a grinding multi-year ground offensives to secure cities and important resource areas by massive ground forces. Only in the most extreme cases wiping out a planet via bombardment.

    1. The 40k universe also has people emerging from flying APC’s wearing powered armour, to stick a sword into a demon. In the name of a God-Emperor who declared the worship of any being, including himself, to be a capital crime. I’m not sure that adherence to the laws of physics is its greatest strength.

      1. “I’m not sure that adherence to the laws of physics is its greatest strength.”

        It’s one of the few space opera settings that doesn’t rape relativity and/or causality to achieve fast interstellar travel. It does this by making the ships fly through Hell, but hey, it’s consistent.

        “In the name of a God-Emperor who declared the worship of any being, including himself, to be a capital crime”

        That was before he died. Then his followers found Emperor-worship convenient. Not the first holy figure to have his teachings slightly altered post-mortem.

        “people emerging from flying APC’s wearing powered armour, to stick a sword into a demon”

        They did prefer to fight at range, when possible. No qualms about close quarters, of course.

        My point is, on closer examination, 40k isn’t as silly as it’s made out to be.

        1. The big problem with 40k and realism isn’t in the physical technology. It’s that the underlying assumptions of the setting are fine-tuned to present the kinds of warfare that Games Workshop wants them to present. Since the marketing for the Imperial Guard revolves around slogging static combat that is essentially “the World Wars, but with ray guns,” the Guard is presented as fighting those kinds of wars. The internal astropolitical logic that makes such wars sustainable and, importantly, *feasible* as the Imperium’s collective response to armed opposition is mostly handwaved with things like “life is cheap in the Imperium” even when, frankly… well, again, it’s logic fine-tuned to justify the merchandising, not the other way around.

  31. The video and your analysis both kinda miss the strategic point.
    Why are we doing this? What are the strategic goals of this fleet vs. planet action?

    The video disregards that point from the position that the fleet weapons can magically surgically cleanze all POI on the planet or do an exterminatus, so it makes sense with that assumption.
    Your approach makes sense if the movement of combatants between planets is as relatively easy and low-tech as moving across the landmass on Earth is. In this case, yes, it also makes sense, because these ominous “they” can easily travel to Ross 248 then to Barnard’s Star then to Earth, so “we” have no choice but put the space boots on the ground of 61 Cygni. If any of stars in there has planets, of course. Otherwise we have to put the space boots on space of 61 Cygni, these are space boots after all.

    Both approaches may be equally fruitful as a setting for a book or a game.

    Realistically it’s hard to imagine the goals of a society in which the costs of the interstellar travel is roughly in the ballpark of preparing a serious off-roading expedition. Such power and mobility (not even mentioning the casual causality violations) is nearly unfathomable, so what they’re willing to die for, how exactly they will fight and in which cases they might surrender will most likely be weird and alien for any karass on Earth.

    However, in a setting where space-faring capability allowing to project power outside of home gravity well is hard, things get easier to understand.
    Depending on the tech level you want to imagine, this space-faring capability requires a hundred of million to ten of million of sapient beings to support. Any lower and it kinda becomes clarketech and falls into a reasoning singularity. A wizar^Wengineer did this.
    So, postulating that, we have a set of production chains, which, if severely disrupted, can disable any power projection outside of the planet for a prolonged time. And they naturally become the strategic target and everyone and their cat knows this.
    We’re back on the familiar territory, hooray, and no need to clean up that suburban area. Again.

    Now, in conjunction with other tech level effects, a severely non-linear dynamics can emerge.
    If both defender and attacker are bound by the same limitations, higher cost of getting things into space means less targets on the surface and higher costs of getting them up again for the defender and less ships and logistical support for the attacker. These bombs and tanks don’t make themselves. If they do, see clarketech. Or Bolo. I like Bolo.
    Lower cost of getting things into space means more targets and lesser downtime of them for the defender and more ships and bombs and space lazors for the attacker.

    That framed, what are their strategic goals?
    Of course, the serious and capable defender should have had a space component of the defense, but as we’re discussing invasions, it’s safe to say these are vaporized and the attacking fleet is quite comfortable in orbit. Sure, the last remnants of the space defense may fight bitterly and rack up much higher personal scores than any of the attacker (as is usual), and not make any dent in the overall space superiority of the enemy.
    The only hope for the defender is to outlast the attacker, while denying him his strategic goals. How to outlast? Depends on the setting. Logistics (fuel, supplies, manpower, equipment, etc) and political will to fight (every tank lost on Cygni 61 is an opportunity cost elsewhere) may be the reasons. Which strategic goals? Good question.

    The only goal that seems attainable at tech levels still visible to us is to confine the defender to his own planet without the ability for interstellar or even interplanetary travel. It’s nearly impossible to make him surrender if he doesn’t want to. The planet is big and is home to billions.
    Maybe the extraction of some rare resource, like unobtanium or bodily fluids, but that’s a MacGuffin at best. Obtaining some knowledge or power is even more dubious.

    So yeah, lock them to their own planet for the time being (it’s clear that over time the defender will build even deeper underground military bases and launch something, maybe en masse) because time is all that matters. They’ll be unable to exert their influence on interstellar politics, participate in the interstellar trade, train insurgents, inflame societal divisions and generally will stagnate and become irrelevant compared to the rest of the interstellar community. That’s all we can hope for.

    So we, as an attacker, need to dismantle their space-faring capability thoroughly and that largely depends on our logistics.
    Surely, one hundred ton of bombs may be equal to one pair of space boots on the ground in the overall combat effectiveness. What we can transport easier to the battlefield? Are the cost of exfiltration of that pair of space boots high? How sensitive are we to military casualties on our side and to civilian casualties on their? Can we produce them in-place? Can we clone these boots on-ship? Maybe it’s easier for us to make bombs in-situ? After all, what you need for explosives is some carbon and some nitro groups, the more the merrier. These are quite abundant in the universe. There’s also the problem of the thermal shield, but it’s solvable too.

    Overall, while different nuances shift the ideal solution into this or that side, bombs seem more likely to save the day. It’s not implausible that we can automate the bomb-making and bomb-deploying even, leaving behind just robots made to slowly ground sentient beings to dust. If we needed a more permanent solution, we’d just use nukes.
    I can think of, but I don’t deem likely situations when a fleet in an already very advantageous position is time-pressed to cut off the enemy world. Surely, there’ll be situations like this and a relatively small cadre of professionals to do this job, maybe blurring the lines to the covert ops and other spooky stuff.

    Now, in video games planetary invasions are a chore.
    Your strategic goal is mostly to own the location of the planet giving you flight range or blocking a starlane chokepoint. Usually it’s much simpler and easier in these mechanics just to ground the population to dust and recolonize the planet without the need to deal with rebellions and what else. Colonization is almost always risk-free and 100% guaranteed to succeed, while invasions aren’t.
    Notable exceptions are:
    — Master of Orion 1 — invasion literally is a population transfer to another planet
    — Distant Worlds and Stellaris — where population grows relatively slow to other 4X games, so you’re forced to do it this way (you just spam armies and land them)
    — Endless Space 1 — where it’s easier just to capture the system by leaving your fleet in-place instead of fitting the ships with something planet-hitting
    — Aurora 4X — because it’s Aurora 4X, you don’t play it to have things in a streamlined way

    Maybe the idea “I’ll just erase them with bombs and move on” stems from 4X experiences.

    1. One thing most 4X games tend to ignore is the question of “how do we actually govern the worlds nominally in our sphere of control/influence?” It’s sort of assumed that once “your population” inhabits a planet, they will smoothly transfer resources and support to the central government, with possible exceptions for “rebellious populations” that have some kind of grudge against you.

      In reality, the problem of ensuring that a far-flung distributed polity actually pays its taxes on time is not a trivial exercise. One of the major cases where the threat of orbital bombardment ceases to work as a trump card is when you’re trying to establish day-to-day compliance with imperial dictates in territory that nominally already belongs to the empire.

      In that situation, you *want* the provinces to be economically productive- otherwise they can’t pay taxes. You *want* the population to survive- see previous. You probably even want the controlling elite of the province to be *mostly* intact after you punish any given act of tax evasion or petty defiance, because it’s too disruptive to have to replace the entire aristocracy after every corruption scandal.

      Which means that a direct attempt to rule by pure, unadulterated force- “fear will keep the local systems in line”- isn’t sustainable. You can devastate a planet whose rulers are actively and credibly conspiring to overthrow the empire, but you can’t devastate every planet whose tax collectors under-report local production totals and send you 80% as much money as they should while pocketing the difference.

      1. The granddaddy of 4X games, Civilization, has Corruption, that increases in cities further from the capital, and in more ‘primitive’ forms of government (like Despotism.) Except for Communism, where you have the same corruption everywhere, and (direct) Democracy, which has none. A city’s Corruption can be halved by building a Courthouse.

        So it’s not detailed, but it’s something, in an old ruleset. Freeciv has experimental rules for population migration.

  32. Bombardment from orbit would be much more effective at destroying armies than historical aerial bombardment, although for a reason that sci fi doesn’t consider. A planetary scale bombing campaign would have significant impact on the climate, by throwing up enough dust to block enough sunlight to cool the planet. Volcanoes have done this historically (Tambora, 1815) and individual hydrogen bombs have similar explosivity. Nuclear winter is a more devastating impact of a nuclear war than the destruction of cities.

    Interplanetary civilizations would be experts at terraforming / geoengineering. I suspect that climate-modifying siege warfare would be more common than dropping bombs. Scatter dust (gathered from asteroids or moons) in the upper atmosphere, reducing the sunlight reaching the planet’s surface by maybe 20%. The cooler temperatures would cause catastrophic crop failures and global famines. Starving a population into surrender has been a common (successful) tactic. And the infrastructure remains intact. The dust stays there for a few months (depending on how high you scatter it), so it can be stopped once they’ve surrendered.

    This is slower, and requires the logistics of keeping a fleet in orbit for months or years. But spacecraft do not require large crews. They would likely be mostly automated and self-sufficient, especially if there are large distances. If the goal is resource extraction / tribute, then you’d never need a significant ground force – deliver the tribute to our launch pad or we’ll cause another global famine. If the goal is a settler colony, then depopulating much of the planet via famine (or biological warfare) is a helpful initial step.

    1. The problem is that the local governing elite and army will tend to confiscate whatever food may exist, making the famine marginally worse for everyone else but ensuring that they will survive.

      Similarly, soldiers in military installations and subject to military discipline are relatively well equipped to ride out biological warfare attacks, at least assuming that we’re dealing with Space Age equipment where things like a certain degree of NBC-weapons protection becomes a must, just to survive. Soldiers’ equipment will be designed with an eye to potentially fighting in very hazardous environments or in places where nuclear or more exotic weapons get thrown around. Normally, pandemics hit armies by surprise. If an enemy fleet shows up to start dropping bio-bombs, it’s a lot easier to get the soldiery into quarantine lockdown inside bunkers with air filtration systems and *keep them there,* assuming they were adequately prepared.

      So while this kind of long slow siege approach works in the end, it’s going to be at least as damaging to the civilian population as to the people whose surrender you actually need to secure… which is a problem if getting the civilians to work for you was part of the goal.

      Furthermore there is, as I mention farther up the page, the problem of how you ensure compliance in places you theoretically already have control or influence.

  33. Robert A Heinlein covered the point about infantry in his Starship Troopers. His narrator observes that while the Navy can crack planets with their latest toys, if you want to control rather than destroy a world you need soldiers on the ground. Nothing else will do.

  34. Mostly, I agree with the thesis, but there is one potential counterpoint I can think of. What if, rather than wanting the planet, you just want to get rid of a potential threat? Conquering is not the objective, but rather to reduce the planet’s technology level so that it never becomes a spacefaring threat. You might, in that case, just want to show up and firebomb all the biggest cities once a generation or so, and this would probably prevent a high-tech economy from surviving. If you view all other species which are acquiring the potential for space travel as a threat, then this might make strategic sense.

    There is also a general trend in which wars become more destructive when the two sides do not regard the other as part of the same larger grouping. Catholics vs. early Protestants, Christians vs. Muslims, Europeans vs. Native Americans, steppe nomads vs. agricultural empires, all tended to have more scorched earth and genocide than when the two sides were not to culturally remote from one another. Since an alien invasion would, by definition, be a bigger cultural gulf than any historical war, we might expect it to be even more prone to genocidal assaults.

    Last point: what about robotic ground troops? At this point, not practical, but it is an interesting question as to what happens when ground troops can be manufactured, rather than recruited.

  35. “How Did They Make It”

    On that point, what periods and cultures would be covered?
    And would frivolous questions like “Could blacksmith of period X and place Y make a sufficiently uniform spool of copper wire of Z length? If so, how much time would it take and how much it would cost?” be tolerated?

    1. I am mostly going to be focused on my expertise – the broader ancient Mediterranean (c. 500 BC – AD 500 or so), but I’m going to gesture broadly at the pre-modern and try to get out of the Mediterranean at least a little bit.

      I’m not going to be getting too deep into technical questions like that mostly, but covering the basics. I may talk about wire production specifically though, since that informs mail armor.

  36. A good post as always and a solid enough argument I want to turn it around: Are there cases ground invasions would be unnecessary?

    I think yes, and I think the “space fleet = air force” metaphor obscures how common this would be. If you have the firepower to destroy a planet’s capacity to manufacture ships, you are are (depending on sci-fi tech, of course) able to advance deeper into enemy territory and completely destroy their ability to make war. If you have a gas giant as a refueling station, the jump point, and have destroyed the capability of a planet to manufacture space ships you’ve done the equivalent of seizing the roads and railway stations in a way that a terrestrial air force could never do.

    I also think the question of surrender needs to take into account the changes in the calculus when you can force planets to do the math piecemeal. If I’m on Alderaan facing the Death Star, surrendering doesn’t end the rebellion but it saves millions of lives. It’s a classic free rider situation. Sure, we might fight like they did in the Siege of Leningrad, isolated and just for the sake of making the enemy pay, but plenty of cities surrendered given that choice here on Earth.

    Which connects to the last scenario: In a war of conquest, if you have the firepower to inflict massive damage–even as “simply” as nuclear winter and radioactive fallout–doing one might render one world useless to you but be a good example for the others. On historical Earth we’ve needed ground troops to take a city and kill the inhabitants (as without troops people flee) but that condition doesn’t apply in space.

    1. the Pacific War is probably a good baseline here. You don’t need to take every island/planet, you only need to take the ones that you want to use for bases, and neutralize enemy bases. If the enemy has a strong point, capture nearby places and cut them off. Just look at how Truk went from unassailable Gibraltar of the pacific to not worth taking in the space of about a year as places around it got captured.

      1. The difference between attacking an island and a planet would seem to be that to attack an island, you have to land an army on the coastline that can fight its way into the interior of the island. To attack a planet you need to land an army on the surface – and that is it. No army can advance into the interior of a planet, so major land operations begin and end with the defenders vertically enveloped, and the important points seized.

      2. Nah, it isn’t that good as a baseline.

        In most cases it’s trivial to get off the island. You can just swim if you can or build a raft.
        Of course, getting somewhere is a completely another topic and without preparation and equipment you’re all but guaranteed to die from thirst, hunger, drowning or agressive fauna.

        However, in a space scenario you can’t even get off your “island” without an equivalent of a frigate, or, if you’re sufficiently advanced, a well-equipped yacht.

        Imagine Tokyo Express, but in space. Kilrathy fleet supplies ground forces under the cover of the night… wait, what?
        Sure, it can work for Chris Roberts, but he wrote a hidden quazar in his movie without blinking an eye.

  37. I think there’s a more fundamental reason that planetary invasion isn’t possible against an enemy capable of hurting you. Space ships full of people are large and hot. You’ll see them coming from a very long way off, and if you’re capable of building fleets of such ships, you’re capable of putting weapons in orbit that can stop them. Missiles that don’t turn on unless ordered to fire, rail guns firing slugs barely warmer than the IR background, a defender can create thousands of such weapon for every troop transport or capital ship. Whatever range the attacker can detect them at, the defender can detect the attacker much further away. Absent super science technology like star trek shields or FTL, I don’t see any way you could ever get close enough to a hostile planet to invade, at least not without astronomical resource disparities.

    1. Although the enemy fleet could fire its own missiles, from a range so great its own ships cannot be targeted. The attackers missiles only have to hit the planet. It is not going to be able to hide, or dodge.

      I cannot help but think of that moment in the Mote in Gods Eye, when someone remarks that conquest is expensive, and allows to hang in the the air the observation that extermination is not.

      1. you could devastate the planet, yes. but you don’t need ships for that, you can chuck rocks or rail slugs from anywhere. Any solar system wide conflict is going to be ugly, like a machine gun fight on a football field.

  38. I’m really excited for the “How They Made It” series! Historical manufacturing techniques are fascinating, both for worldbuilding/fiction reasons and for the impressive skills involved.

  39. You can probably pick your SFnal parameters to justify whatever outcome you want. Xenocidal war between species or idealistic war of ‘liberation’? (If you’re out to free the slaves it’s poor practice to kill them all.) Strong AI or not? Realistic space travel or magic FTL? Do falling rocks bounce off of force fields, or get caught and thrown back by pressor beams?

    Resource extraction: in one scenario you’re out to dismantle the planet to build Dyson swarms, in another you’re looking for minerals that have been selectively concentrated by planetary hydrology, in another the resources are biologicals or manufactures.

    If we’re trying for a ‘realistic’ invasion, one thing the rock droppers overlook is heat dissipation. Space is a Thermos bottle, and warships generating lots of power need to dump lots of heat. Which means radiators. Nice, fragile, radiators that can be shot at even from a planetary surface. Conversely, a planet like Earth has *oceans*. Giant heat sinks of water. Also, stealth in space is nigh impossible given real tech.

    So even if the invaders have swept aside the home defense in space, you may have orbital battleship and missile carriers, utterly visible, fighting submarine laser platforms that can move around stealthily underwater, pop up to blast away at orbit, and dive again to dodge and cool off.

    If you can support populations for a long time in space, then the same technologies can be used on planets. Ordinary life may have surface cities and farms but there may also be Swiss+ bunkers for the whole population, complete with nuclear reactors and redundant hydroponic food production. The sort of thing that can tide you through alien invasion *or* various catastrophes[1].

    If you can’t support populations for a long time in space, then the invaders have a ticking clock. (Though also, how did they get here?)

    Also if you’re being realistic, moving big rocks is not actually at all easy, especially on a short time scale. It’s doable, but energetically expensive. Conversely, spaceships don’t move around like airplanes, or even like seaships; they move like trackless trains. You spend a lot of delta-vee heading somewhere, and you spend a lot of delta-vee stopping there. Carrying enough delta-vee to make a return trip makes it all more expensive, because of the rocket equation. Fancy maneuvering is “haha no”.

    Websites of interest: projectrho, rocketpunk-manifesto.

    [1] One argument made for space ‘exploration’ and colonization is not having “all your eggs in one basket”. Speaking as one of the eggs, I would rather harden my own basket before sending eggs to other baskets, especially when the former is much cheaper.

  40. The video seems a lot like a mistaken view of a lot of military theorists in the fifties – now that there are nukes, all warfare is going to be just about the nukes. As long as you can deliver nukes to your enemy and not get nuked yourself, you will win any war. Nukes are all that matter. A country with nukes can just extort a country without them freely. (My home country, peaceful neutral Sweden, had both a nuclear weapons programme and a ridiculously powerful air force that was intended to *stop every Soviet nuclear bomber*.)

    This view collapsed under the combination of terror balance and public opinion. It doesn’t seem inconceivable that something similar could happen in a space war – galactic society may think that while wars are something that’s going to happen, destroying entire rare biospheres is simply beyond the pale, and something that you need to be smacked down for if you try. And if it’s sufficiently easy to throw rocks on planets (check out next season of The Expanse), then there might be a terror balance here as well.

    Note how the Centauri become something of space pariahs after hitting Narn with mass drivers (as seen in the video). It doesn’t end well.

  41. Great blog, as ever!

    This might come over as blowing my own trumpet a bit, but I addressed this in my unpublished short novel (written as a NaNoWriMo project), called Rules of Engagement. This story has inter-planetary warfare purely as an effectively imperial exercise to re-gain control of a rebellious colony – no aliens, just various humans, including genetically modified ones. In fact, I wrote the book as an exercise to show that orbital bombardment would simply harden the population, not conquer it, pretty much regardless of the military prowess or indeed brutality employed, on the understanding that the would-be conquerors wanted something from the target planet. IMHO there are some interesting characters too, but I’m not a professional fiction writer, so I’ve no idea whether the book’s any good.

    If anyone’s interested, I wrote this little snippet as a pseudo-academic critique of a theory of planetary attack:

    “Military historians divide a conventional planetary attack into four main phases, following the theories of
    Rosemary Stagg, the great 21st century theorist of war: Orbit, Air, Bridgehead, Exploitation (sometimes
    called Capture). Each phase must be successfully completed before the next, or the whole operation is
    at risk. Although there had never been a planetary attack when Stagg wrote her seminal work ‘How to Conquer
    Planets’, her analysis is generally viewed as highly perceptive and has formed the starting point for military
    historians of later conflicts.

    “In the Orbit Phase all defending space borne systems must be neutralised. Even residual defensive orbital
    capability, typically active bases on moons or near orbit stations, places the later phases at significant risk, according to Stagg’s theory. So time taken at this stage to seek out and destroy enemy systems
    comprehensively pays dividends.

    “The Air Phase starts only when all orbital defence systems have been eliminated. Now the attacking
    forces can use their own orbital systems to suppress defending atmospheric craft and surface to orbit
    weapons systems. The principal advantage seems to lie with the attacking force, which can choose
    when and where to strike. However, as Clausewitz notes, ‘the defensive form of War is in itself stronger
    than the offensive…the defensive is always certain of the assistance of ground, which ensures to it in
    general its natural superiority’. The attacker knows not where the defender’s forces are, unless the defender
    reveals them. So as the defender’s main objective is to gain time, he will use only part of his forces
    in any one operation, unless a decisive action is possible. The attacker meanwhile needs only to gain
    a local control of the air, not total air control over the whole planet, in order to pursue the next phase of
    his operation. Air superiority however is insufficient, leading inevitably to inflated and prejudicial losses
    in the attackers’ orbat.

    “The Bridgehead Phase is possibly the most mis-understood of Stagg’s theories. Some have interpreted
    this phase as simply an assault on the planet’s surface to permit the deployment of more forces that will
    enable the exploitation – conquest – of the entire planetary surface. However, this is a misconception.
    Stagg describes the Bridgehead Phase using the analogy of a weighted net used by hunters to bring
    down large quarry. Stones tied to the net inhibit the animal from freeing itself, while enabling the hunter
    to jab at the animal with a spear in relative safety. The purpose of the weighted net is to prevent the
    animal from escaping or from hurting the hunter, in other words to guarantee the hunter’s victory. In the
    same fashion the purpose of the Bridgehead Phase is to severely limit the remaining freedom of action
    of the defending forces, particularly their offensive capability, so that it is only a matter of time before
    the defenders succumb. According to Stagg therefore, the Bridgehead Phase is likely to involve several
    co-ordinated assaults designed to cripple the defender’s ability to carry out offensive operations. If the
    defending forces are widely scattered, then the assaults may be likewise scattered, which suggests that
    the attackers are breaking the rules of strategy which state that forces should be concentrated upon
    one objective at a time. This criticism overlooks the particular nature of planetary attack after the Orbit
    Phase; it is precisely the success of the Orbit Phase that knits the attacking forces together. With no contest
    in orbit, the attacking forces are linked by their ability to support each other via space-borne means,
    and each individual assault forms part of the greater whole. Confusion here has perhaps arisen, because
    of Stagg’s use of the singular ‘bridgehead’, rather than ‘bridgeheads’. A close and comprehensive reading
    of Stagg’s text reveals the true nature of the Bridgehead theory.

    “The Exploitation Phase is simply explained. Once the immovable rocks of the Bridgehead have been
    established, the attacker can reinforce at will, while the defender is subject to attack from orbit, from the
    air and from the ground, with no prospect of relief. A problem for the attacker remains. Has he sufficient
    forces to complete the operation? Again, following Clausewitz, Stagg reiterates that the defender merely
    has to have some forces left and to await events. It is the attacker’s duty to complete the conquest.

    “Assault from Space: Rosemary Stagg’s theory of planetary attack explained”

    1. With regard to the scenario in the novel you mention, don’t rebellious colonies often require assistance from a third party to successfully rebel in the first place – especially if the purpose of a colony is resource extraction, and the central authority has thus had no reason to furnish them with the means to manufacture their own advanced arms and vehicles?
      Although I suppose a possible exception might be a scenario where the ‘rebel colony’ was in fact a fully integrated part of the empire(?), but loyalist to a previous central authority which has been overthrown by and replaced with the current central authority, which is now mopping up loyalist holdouts after the coup/civil-war.

      1. Yes. Or, conversely, the rebellious province may be loyal to a rival claimant who aspires to take the central authority’s throne out from under it. In such situations you may see multiple mutually supporting provinces rebelling at the same time, and as you mention, you may also see fully integrated provinces rebelling. Provinces that have enough of their own industry and war economy to be capable of independently maintaining or outright manufacturing their own weaponry.

  42. Attempt number 2:
    “Military historians divide a conventional planetary attack into four main phases, following the theories of Rosemary Stagg, the great 21st century theorist of war: Orbit, Air, Bridgehead, Exploitation (sometimes called Capture). Each phase must be successfully completed before the next, or the whole operation is at risk. Although there had never been a planetary attack when Stagg wrote her seminal work ‘How to Conquer Planets’, her analysis is generally viewed as highly perceptive and has formed the starting point for military historians of later conflicts.

    “In the Orbit Phase all defending space borne systems must be neutralised. Even residual defensive orbital capability, typically active bases on moons or near orbit stations, places the later phases at significant risk, according to Stagg’s theory. So time taken at this stage to seek out and destroy enemy systems comprehensively pays dividends.

    “The Air Phase starts only when all orbital defence systems have been eliminated. Now the attacking forces can use their own orbital systems to suppress defending atmospheric craft and surface to orbit weapons systems. The principal advantage seems to lie with the attacking force, which can choose when and where to strike. However, as Clausewitz notes, ‘the defensive form of War is in itself stronger than the offensive; the defensive is always certain of the assistance of ground, which ensures to it in general its natural superiority’. The attacker knows not where the defender’s forces are, unless the defender reveals them. So as the defender’s main objective is to gain time, he will use only part of his forces in any one operation, unless a decisive action is possible. The attacker meanwhile needs only to gain a local control of the air, not total air control over the whole planet, in order to pursue the next phase of his operation. Air superiority however is insufficient, leading inevitably to inflated and prejudicial losses in the attackers’ orbat.

    “The Bridgehead Phase is possibly the most mis-understood of Stagg’s theories. Some have interpreted this phase as simply an assault on the planet’s surface to permit the deployment of more forces that will enable the exploitation – conquest – of the entire planetary surface. However, this is a misconception. Stagg describes the Bridgehead Phase using the analogy of a weighted net used by hunters to bring down large quarry. Stones tied to the net inhibit the animal from freeing itself, while enabling the hunter to jab at the animal with a spear in relative safety. The purpose of the weighted net is to prevent the animal from escaping or from hurting the hunter, in other words to guarantee the hunter’s victory. In the same fashion the purpose of the Bridgehead Phase is to severely limit the remaining freedom of action of the defending forces, particularly their offensive capability, so that it is only a matter of time before the defenders succumb. According to Stagg therefore, the Bridgehead Phase is likely to involve several co-ordinated assaults designed to cripple the defender’s ability to carry out offensive operations. If the defending forces are widely scattered, then the assaults may be likewise scattered, which suggests that the attackers are breaking the rules of strategy which state that forces should be concentrated upon one objective at a time. This criticism overlooks the particular nature of planetary attack after the Orbit Phase; it is precisely the success of the Orbit Phase that knits the attacking forces together. With no contest in orbit, the attacking forces are linked by their ability to support each other via space-borne means, and each individual assault forms part of the greater whole. Confusion here has perhaps arisen, because of Stagg’s use of the singular ‘bridgehead’, rather than ‘bridgeheads’. A close and comprehensive reading of Stagg’s text reveals the true nature of the Bridgehead theory.

    “The Exploitation Phase is simply explained. Once the immovable rocks of the Bridgehead have been established, the attacker can reinforce at will, while the defender is subject to attack from orbit, from the air and from the ground, with no prospect of relief. A problem for the attacker remains. Has he sufficient forces to complete the operation? Again, following Clausewitz, Stagg reiterates that the defender merely has to have some forces left and to await events. It is the attacker’s duty to complete the conquest.

    “Assault from Space: Rosemary Stagg’s theory of planetary attack explained”

    1. I don’t quite follow, I’m afraid.
      The bridgehead(s) phase is aimed at securing the initiative for the attacker (ok) by forcing predicted responses from the defender, thus eliminating defender’s advantage (o…kay? might work) by… placing immovable rocks?
      What’s that, a siege of Vraks?
      Maybe “immovable rocks” are metaphoric, aimed to illustrate the indomitability of supply lines and operational and tactical mobility, the freedom to strike at will, but even in this case it’s a bit too complex analogy.
      I guess, you need to have a pretty high IQ to understand Stagg.

        1. Yeah, with metaphors like this it’s no wonder this was the most misunderstood theory.

          Very nice injection of humanities and their impact on the military theory, btw.

  43. There are space opera novels where “space power” alone (or its threat) is successful in a matter that “makes sense”. In the examples that I can think of, the relevant factor that avoids the issues mentioned in this post is that achieving control of the planet is not the goal; instead, the objective of the space side is considerably narrower. I will refrain from discussing the instances of this issue in The Expanse, as it is also a popular TV show and I might spoil forthcoming seasons.

    In Alastair Reynolds’ “Revelation Space”, there’s an archaeological colony in a planet, comprised by a small city and some smaller settlements around the planet. At a certain point in the novel, a key character is imprisoned by the local government in the “capital”; however, this man (Dan Sylveste) has something of great interest to the three-strong crew of a massive spaceship equipped with a selection of the Revelation Space universe’s equivalent of WMDs. The crew demand that the local government hand him over to them, they refuse, they issue a first ultimatum, the government refuses, and the spaceship wipes out a single settlement, threatening another strike. At that point, they surrender Sylveste. It’s basically Hiroshima/Nagasaki but with a much narrower goal against a much less powerful enemy, so it definitely works narratively.

    As an alternative example, I’m also a fan of John Lumpkin’s novels ( http://www.thehumanreach.net ), where he tries (quite successfully, in my opinion) to do “realistic” military space-battles and geopolitics. In the books, planetary invasions and boots on the ground are definitely necessary to occupy/control a planet. The author’s background as a natsec journalist and war reporter definitely shows. Sadly I’m not sure if there is ever going to be a third novel, since he moved to full-time videogame development after the success of the XCOM “Long War” mods, which he developed among others.

  44. An interstellar empire that wants people and planets, like Anne Leckie’s Radch, after figuring out the language (if you want the people to surrender it helps if they can tell you they give up), starts by destroying the major cities and military installations. I seem to remember that the next thing the Radch do is to conscript the children and younger members of the ruling elites as “ancillaries,” which are basically meat puppets. The soldiers (many of whom are meat puppets controlled by remote ship AIs) also wear armor that’s invulnerable to small arms.

    A polity capable of routine routine interstellar travel will be in possession of technology far beyond what is present on Earth. How well would a group of hoplites do when faced with Napoleonic infantry, let alone a modern armored unit?

    1. Pikes were still used (occasionally) even after the Napoleonic wars. Hoplites might do reasonably well charging against Regulars, but grape shot would be lethal.

      Hoplites vs tanks on a remote island is a no brainer – the tanks will run out of gas, whereas the ancients hunt and fish their “fuel”. The spears must avoid a decisive confrontation while the tanks have power, then they’re set.

      Hoplites vs tanks on a modern battlefield is of course a no-brainer too. Guess what, they’re both optimized for their own battlefield conditions!

  45. I think a problem is one of motivation and technology level.

    Basically, unless we scrap the laws of physics (so no time travel or faster than light travel), there’s only a small technological window where you would need to conquer/colonize a planet – and thereby keep it relatively intact. If your technology is at too low a level, then you won’t be in space in the first place, and if it’s too high, then there is no reason to want to colonize a planet; space based habitats can offer anything that a planet can without the problem of being at the bottom of a huge gravity well. Most of the mass of a rocky planet is for all intents and purposes inaccessible

    If you are just prosecuting a war, then simply destroying the technological infrastructure from orbit is fairly easy, and politically, ‘We’ll stop dropping rocks on you if you stop shooting up at us’ is a reasonable agreement to make.

    The only scenario that I can think of to get here is:

    – Aliens from 1000 light years away see Earth (as per 1k years ago) – no sign of intelligent life. They build a sleeper/generation ship right at the limits of their technology, on the basis that when it reaches it’s destination, there will be a pristine habitable planet to occupy.
    – They arrive to find humans with a technological society swarming all over the place.
    – Now they have a genuine dilemma. They could drop enough rocks to snuff out humans, but that would leave the planet uninhabitable. And they may not have the numbers for a full boots-on-the-ground campaign.

    The one thing that springs to mind here are chemical and biological weapons. These can be made species-specific – so you would just be eliminating the troublesome inhabitants, and possibly their crops/livestock. There would no doubt be survivors, but very few and with no industry.

    But outside of that, I can’t see a scenario that makes sense. Mind you, having the West invade Afghanistan doesn’t make much sense either..

    1. That’s probably why aliens abduct cattle and humans and do all kinds of experiments and then release humans back.
      They indeed need our bodily fluids. But for SCIENCE.

      The only explanation why we’re still alive and kicking is that their biology is surprisingly similar to ours.
      Their science isn’t magical, their immune systems are running at very low capacity, so for seventy years they dutifully try to find a virus that will kill us and won’t kill them after any reasonable number of mutations.
      It’s like they’re plaing Plague Inc. on the very hard mode and have only one attempt.

      Also, there weren’t many abduction reports for last thirty years, so they might have killed themselves by playing with biological fire.

      It’s unlikely they’d go with chemical weapons and terraformation without our help.
      Sturgeon wrote about it fifty years ago in his ‘Occam’s Scalpel’. A bit obscure nowadays, but highly recommended.

    2. “space based habitats can offer anything that a planet can”

      Not really.

      Habitable planets are giant, self-sustaining, self-regulating, truly-freaking-gigantic life support systems.

      Also, extremely resilient. Think how much firepower it takes to kill a planet (Chixculub was a few billion gigatons and failed to kill everything), vs an O’Neill cylinder (a few tons of TNT would do the job). Think how much time you have to evacuate, if it does happen (planet – years; habitat – seconds).

      Also, built-in radiation protection, via huge atmospheres and (where available) magnetic fields.

      Also, really big, varied, resilient ecosystems. I’m not currently aware of any successful artificial ecosystem, so we don’t even know if the minimum viable size is much smaller than a continent.

      “without the problem of being at the bottom of a huge gravity well”

      Sure, but a space-faring species might know how to deal with that. Lofstrom loop, space elevator or just really simple, really big rockets. And you wouldn’t bring up anything except people – resources are plentiful up there.a

  46. I’m using this, because I do not, ever, twit.

    I really want to thank you for this post. I have been screaming the same thing for literally many decades… and what’s worse, generals and “terrorists/freedom fighters” are ALL USING THE SAME DAMN PLAYBOOK, they’re *all* trying to break the will of the people to resist.

  47. By the way, commenters: all these empires that have rebellious colonies? They all seem to assume that it’s *only* a few colonies, and they’re all not very terraformed or industrialized. You might ask the US military how well they’ve been doing trying to have enough troops and planes in subduing the Middle East….

    Planets are BIG (step outside for a while, or go places like the Rockies). If the colony’s been around for a long time, we’re talking many, many millions of people… and you will run out of ships and armies.

    And, of course, as this goes on, sooner or later you run across a colony that is ready and waiting… and takes over your ships….

    Meanwhile, your navy is not set up to conquer or reconquer colonized worlds, it’s there for shipping, and pirates, and other polities. When my new novel is published, you’ll see how I handle it….

  48. What if the goal is not occupation, but containment? In other words, neutralizing a threat or potential threat by destroying their offensive capabilities? Do you think airstrikes/orbital bombardment, possibly followed up with a blockade, could be an effective strategy in that situation?

  49. Since this is a science fiction scenario, the first step is to make assumptions explicit, or at least be aware of how important unstated assumptions are.
    I welcome Dr Devereaux’s question “why”. Is the attack for resources, or to control the population? If the planet being attacked is not the sole population base of a polity or alliance there are other possibilities, for example it could have a strategic location or contain a strategic resource. If the “why” of the defence is that it is only desired as a base by its owner, then the population might only be able to live in sealed environments or be reliant on blockade-able imports.
    Secondly, what technologies are used? If we assume that the weapons are a continuation of artillery, then the issues of cost and mobility come into play. A battleship’s main armament can be located on land, at a great saving, but unless sited where an enemy is likely to or must attack it could well be wasted. This could be scaled up in the case of starships. That is, a starship’s main battery could be most cheaply located in fixed sites on a planetary surface (perhaps its secondary armament be made mobile on a planetary surface), the battery could with more expense be distributed over a number of waterships that use a planet’s oceans, then more expensively be placed on satellites, then an intrasystem vessel, and most expensively a starship. An attacker could create a blind spot in planetary defences, then exploit it, so perhaps the defender should concentrate on intrasystem weapon platforms. The cost advantage of these vessels (compared to starships) is going to be partly eroded by the defender’s need to either heavily defend their bases or make them relatively base-independent with regards to supplies.
    What sort of cannons? If some sort of shell then planet based munitions must rise against gravity. If missiles they may be easier to track than shells, and more cost effectively destroyed by the attacker’s defensive weapons. Missiles are less vulnerable to the blind spot problem, but would still have the cost of being able to overcome gravity. Some sort of beam?
    But as stated above this is a science fiction scenario. The two sides may have quite different technologies. And why not biological weapons, especially if the defender’s environment is open, rather than comprising cities sealed to the atmosphere? “People of the earth, surrender to our forces for the antidote, or that cold you all got will kill/madden/sterilise/blind you in two weeks”.
    Thirdly, what are the cultures of the parties? Culture will grant permissions and impose prohibitions.
    Goals, technology and culture will interact. Playing around with the 3 can produce many scenarios which will alter the balance between defender and attacker. The defender will certainly be asking “what do they want, what can they do and what are they willing to do”.
    I have assumed that there are 3 main assumptions, which may itself prove to be wrong, but one can only start from where one is.

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