Collections: Global Trade and United States Navy

This week we’re doing another one of our series of military theory primers, this time focusing on a fairly simple contention: that the United States Navy is a load-bearing component of the global economy. I considered attempting to work in A.T. Mahan and the concept of command of the seas in here but simply outlining the basic argument about the navy’s role in sustaining global standards of living has run out more than 10,000 words, so a primer on Mahan will have to wait for another day.¹

The argument here is actually quite easy to state as a series of propositions: global trade is an important part of the global economy, necessary to maintain our standards of living (and in many cases, essential for the survival of people in poorer countries) and seaborne trade makes up the overwhelmingly vast majority of all trade. Moreover, in history to this point it has been a relative constant that in the absence of major naval powers committed to freedom of navigation, pirates and states at maritime choke-points tend to emerge and seriously disrupt maritime trade. Finally, at current, only the United States maintains the kind of navy that traditionally has been necessary to keep sea lanes open, thus making the US Navy at present a ‘load bearing’ component of the global economy. Consequently, this makes the United States’ apparent turn away from freedom of navigation troubling – a move likely to be bad for Americans but also bad for everyone else.

If you nodded your head through all of those points, you are good to go. Hit the tip jar on the way out. But I find that many folks want to contest at least one of those points – they don’t think trade is important (or that it only enriches ‘big corporations’) or don’t realize how substantial sea trade is, or don’t expect sea commerce to break down in the absence of naval power, or don’t understand the kind of navy necessary to provide that sort of power. So the rest of this far-too-many-words-long post (it turned out to be 10,430) is going to belabor each point, one by one, in order to explain why the United States Navy – which I should stress is very much an imperfect institution; we are not here to uncritically glaze the USN, just to describe its function – is configured the way it is and why there is not currently a replacement for it on offer.

Also, let me note at the beginning: if you want regular updates on global shipping as well as good explainers about how global shipping works, I cannot recommend Sal Mercogliano’s What’s Going On With Shipping channel enough.

But first, as always, building navies is expensive. Really expensive. Absurdly expensive. If you want to help keep this ship afloat, you can help by spreading the word to new readers and by supporting this project over at Patreon. If you want updates whenever a new post appears or want to hear my more bite-sized musings on history, security affairs and current events, you can follow me on Bluesky (@bretdevereaux.bsky.social). I am also active on Threads (bretdevereaux) and maintain a de minimis presence on Twitter (@bretdevereaux).

A World With Trade

Now I want to start by talking about what global trade really is and its role in the global economy, because in many cases before I can get to anything about shipping lanes and choke points and pirates and so on, I find many regular folks have already immediately objected that they do not care about global trade. They think of global trade as a thing which mostly benefits big corporations or ‘cosmopolitan globalist’ elites. But, you must pardon me, they are wrong: they do not yet know that they care about global trade. When global trade is disrupted – even just a relatively little bit! – and the price of a barrel of oil nearly doubles, leading to a one-third surge in the price of gasoline and a 50% jump in the price of diesel, it turns out they care a great deal.

They often just don’t think about that in terms of global trade, because global trade is one of the key things that makes modern prosperity possible, mostly invisibly. That very invisibility, as we’ll see in the end, is part of what poses real political problems, but let us first make trade a bit more visible.

The first mistake that folks make here is to assume that trade is a relatively small part of the global economy. It is an easier mistake to make in a place like the USA, which is very big and thus trades with itself more than most, but globally trade makes up between a quarter to a third of all economy activity.² That is, it turns out, quite a lot. If your household income fell by a third, that would be very difficult for you. If every household’s income fell by a third, the resulting economic contraction would be double the size of the Great Depression (which reduced global GDP by roughly 15%) and have all sorts of knock-on effects as those households themselves had to cut back on other, non-imported goods and services.³

The second potential mistake here is to assume that all of this trade is mostly a luxury: that it just accrues to the rich or to rich countries or to big corporations. We may remove the ‘rich countries’ here right off: a lot of the countries with very high trade-to-gdp ratios (imports+exports, thus the ability to exceed 100%) are poor countries (the other big group are small, rich countries): countries like Vietnam (190%), Djibouti (206%), Namibia (108%), Somalia (128%), Libya (137%), Guinea (103%) and so on. We’ll come back to this in a moment, but a breakdown in global trade is actually especially bad for poorer, developing countries.

Likewise, while big corporations surely profit off of trade – no poor man ever owned a freighter – they’re not the only ones. We can think about this by thinking about the most staple of all bulk staples: food.

In the developing world, access to global food markets is an essential lifeline. Most developing countries, especially across Africa, are net-food importers, some quite substantially so. Moreover, whereas food imports in developed countries are often ‘exotic’ foods that grow in other climates (think bananas away from the equator), for developing countries, these are often bulk staples. As we saw in 2008-2010 and again in 2022 and may grimly see again soon, increases in the price of bulk stable foods are associated with political instability and suffering in the developing world. Because if the price of bread goes up by 25% in the United States, for most Americans that is annoying, but in many developing countries it means people go hungry because they cannot afford food.

Developing countries are also more likely to have agricultural systems that are exposed to more variability (drought, pests, blight, etc.) as compared to developed countries. And fundamentally everyone relies on trade to insure against famine in the event of a local failure in food production. Trade is what allows us to even out a freak drought in one country or a flood in the other to keep everyone fed. That trade may be in the form of market interactions or it may arrive as foreign aid or disaster relief, but it is still the movement of goods from one place, from one country, to another.

Trade is also important for the developing part of developing countries. Doing the industrial revolution from scratch – designing and building better steam engines, creating factories, developing precision tools, steadily expanding production as all of that industrial capital accrues – took Great Britain something like a century and a half (roughly 1750 to 1900 – we’re being quite approximate here) to hit an economic standard we might define as ‘middle income’ today.⁴ But developing countries today that have access to trade – and here we mean not just the movement of goods (but also that) but also people – can go through that transformation much faster. The classic interaction is that developing countries sell raw materials⁵ to import the machinery and experts to build basic manufacturing industries (think steel, concrete, agricultural goods processing and so on) and then sell those goods to be able to afford to important the experts (including educators) and advanced equipment to make more complex finished goods. Because manufacturing, say, a car requires not just raw materials, but the ability to craft high quality materials (like very precise steel alloys) as well as very complex components and very precise parts within low tolerances and that both requires really fancy manufacturing equipment (which also requires those same high quality materials, complexity and low tolerance components to build) and very skilled workers, designers and engineers.

Trade allows developing countries to jump-start progress on each rung of that ladder, importing the experts who already know how to do these things (and can teach more) and importing the machines that can do these things (with which more may be built), ideally resulting in a high-income, more self-sufficient economy achieved in decades rather than centuries. And you can see any number of countries that either have accomplished this (China, Japan and South Korea, for instance) or are now accomplishing it (India, Vietnam), often from very low initial industrial ‘baselines’ (frequently as a result of tremendous neglect or malice at the hands of European imperial masters).

As those developing countries work their way up the value chain from raw materials to basic goods (often textiles) to low-cost, low-complexity consumer goods (e.g. plastic toys) to higher complexity consumer goods (cars, washing machines) to the very top of the value chain (software, aircraft, etc.), their standard of living improves, but equally because the cost of labor in those countries is lower, they provide much cheaper goods to developed countries. Those cheaper goods in turn lower the cost of living in developed countries, making the sort of ‘American Dream’ middle-class lifestyle available to more people.

Of course even among developed countries, trade does not lose its value – there are forms of comparative advantage that have nothing to do with labor costs. Some industries are so large, technical and expensive that few countries are big enough to absorb the entire demand of it – aeronautics is a classic example. It might make sense for some countries to specialize in aircraft production, but most countries are too small to have a domestic aircraft manufacturer just for the heck of it – they’d be better off specializing in something else and using that product to buy the planes. Meanwhile, some goods are simply hard to produce in certain places: Norway is never going to grow many bananas, Japan is probably not going to ever be a major producer of oil, Mali is not going to export much in the way of fish.

All of which is to say that trade directly improves the living standards of regular people in both developed and developing countries and equally, we do a lot of it, with trade representing something approaching a third of the global economy.

All of which now brings us to the key observation: 80% of all goods transported globally move by sea. That is a figure which is too big for bold, so let’s step it up a bit:

80% of All Good Transported Globally Move By Sea

There we go.

So not only do more goods move by ship than by aircraft, railway or truck or river barge or what have you, four times more goods move by ship than by every other alternative system of transportation combined. And if roughly 30% of global GDP is goods being traded, that means that about a quarter of global GDP moves by ship each year. That is a very big part of the global economy!

The main reason for this is simple: it is much cheaper to move goods by sea than by any other method. For the cost of sending one shipping container across the United States by land (truck or rail; when I checked in 2023 around $2,500-7,500, with some variation by weight and exact route) you could also ship that same shipping container from an American cargo port to any port in the world at all (around $6,000). Shipping by sea is (this is the rule of thumb I was given a few years back when I asked) around three times cheaper than rail, five times cheaper than truck and eight or more times cheaper than air freight. That is an enormous cost difference.

Believe it or not, that huge difference in cost is actually less than it was before railways and internal combustion engines made bulk overland transport somewhat affordable. In antiquity, the ratio of cost (derived from Diocletian’s Price Edict) for transport between land, river and sea was 20:4:1, with land transport for a given quantity of bulk staples being twenty times as expensive as land transport. With the miracles of the industrial revolution, we’ve brought down ‘twenty times as expensive’ to merely! three to five times as expensive, per ton-mile.

There are two basic reasons for this. One is that it simply takes less energy to move things over water than it does to move them through the air or overland. But the other reason, that I think is worth stressing here is ships can be really, really big.

A truck can move a single cargo container. A typical freight train might have 100 or so freight cars each moving about a cargo container. A large Suez canal capable container ship, by contrast, might carry upwards of 20,000 TEUs (twenty-foot equivalent units, the size of a cargo container). That means a single container ship might match the cargo capacity of hundreds of trains or tens of thousands of trucks. That holds true for other kinds of freight: a tanker truck can move about 200 barrels (bbls) of liquid, like oil. Suezmax tankers can get up to a million bbls and Very Large Crude Carriers (VLCCs) are often in excess of two million.

So the scale that sea shipping can operate on is simply much greater than what is currently possible on land. Even pipelines for oil generally move less than active major shipping lanes (as we’ve seen demonstrated in the Strait of Hormuz) and of course you cannot move iron ore or consumer goods or grain via pipeline but you can move them in large freighters. As a result, nearly all long-distance trade moves as far as it can by ship before transferring to truck or rail for the ‘first mile’ and ‘last mile’ of its transit. It is thus far to say that global trade – which, as we’ve established, is an important part of the global economy which enables rich countries to eat well and poor countries to eat at all – is mostly about shipping on the water.

Strait Up Piracy

All of that seaborne trade, however, is the product of a long period since 1945 in which there have been relatively minimal disruptions of the security of civilian ships moving over the world’s oceans. What I want to note is that this is not automatic, it is an outcome that has been produced. Instead, the historical pattern has generally been that in the absence of major powers exerting themselves to keep sea lanes open (because it benefits them to do so), what we see is that sea trade fragments, with polities sitting on maritime choke-points moving to exploit that control (at the expense of everyone else) and both pirates and privateers disrupting shipping more generally.

Piracy, of course, is extremely old: it is treated as a well-established and perfectly normal thing to be doing in Homer, for instance. We actually have references to sea raiders and pirates even farther back, including in the Amarna tablets (c. 1350 BC). Now I should note that while we generally think about piracy as ships attacking ships, there is a land based component to it: piracy often also includes the raiding of coastal settlements and at the same time pirates themselves need coastal bases (often with friendly local populations) in order to operate out of.

Notably, a lot of this early evidence for Mediterranean piracy comes in the context of the Late Bronze Age Collapse and the period immediately following it (the latter including piracy’s place in Homer’s conception of maritime activity, where it is a normal and regular thing to be doing), periods of state fragmentation where there weren’t any major naval powers in the Eastern Mediterranean capable or willing to enforce freedom of navigation. That changes as we move into the Late Archaic and Classical periods (as reckoned in Greece, so c. 550 BC onwards): the Achaemenid Persians are able to dominate effectively the entire litoral of the Levantine Sea (the part of the Mediterranean between Egypt and Anatolia) and maintained a strong navy – and we hear a lot less about piracy in this period. Later emerging Greek naval powers (particularly the Athenian navy after 483) also had an interest in piracy suppression – Athens was reliant on imported grain and timber and also profited immensely from trade.

That state of affairs continues broadly until the death of Alexander, where we get a resurgence in our evidence for piracy in the context of the Wars of the Diadochoi. Our visibility here is better and one thing worth noting is that piracy here dovetails with what we might term privateering – state-sanctioned piracy – as some of the Macedonians scrapping for control (Demetrius Poliorcetes most notably) hired pirates and mercenaries to harass their enemies. Men might move smoothly from being mercenary sailors in the service of a king to ‘pirates’ and back again while doing effectively the same things on the water. That said, these states also had an interest in trade (especially Rhodes) and so alongside the piracy were efforts in piracy suppression.

This system famously gets out of hand when the Romans in the mid-second century destroyed or crippled most of the major maritime powers of the Eastern Mediterranean (Macedon, the Seleucid Kingdom, the Ptolemaic Kingdom, Rhodes, Pergamum) but didn’t move into the region to replace them. This ends up leading to a series of relatively Roman commands against pirates in various parts of the eastern and central Mediterranean: L. Fabius Labeo in 189, M. Antonius in 102, L. Licinius Lucullus in 86, P. Servilius Vatia in 78, M. Antonius Creticus in 74, L. Caecilius Metellus in 70. This eventually culminates in Cn. Pompeius (Pompey)’s famous command against the pirates in 69, where he was given unprecedented authority to operate basically everywhere in the Mediterranean (using subordinates to coordinate distant activity), a command whose overweening scale is one of the major marker points in the emergence of the Late Republican ‘rogue general’ in Roman history.

Pompey’s success here is, as far as I can tell, actually emblematic of how anti-piracy campaigns succeed: he targeted the pirate’s coastal bases, not their boats and used the coercive threat of force to negotiate rather than just trying to wipe out all pirates. In the end, Pompey smashed some strongholds and used the leverage the threat of that gave him to resettle the pirates (and their supportive populace) inland, away from the coast. Roman piracy suppression after Pompey is much more successful: as Roman controlled effectively the whole Mediterranean litoral, it could deny pirates bases everywhere – although through the imperial period the Romans still had to maintain a navy to keep the trade lanes, upon which their empire’s prosperity relied, open.

To simplify greatly, we see a similar set of processes in the ‘Golden Age of Piracy’ (c. 1650 to c. 1730). It was enabled by state fragmentation and warfare, particularly the rivalries between England and France to one side and Spain on the other. It ended in part because those wars ended, but notably also with the application of the same mix of coercion and negotiation, perhaps most famously with the destruction of the ‘Republic of Pirates’ at Nassau – many pirates took the offered ‘King’s Pardon’ leaving the remainder isolated enough to be destroyed in detail and for British power over the Bahamas to remove the coastal bases necessary for piracy.

And we see a similar interaction with the Barbary Pirates in the Mediterranean. The activities of the Barbary pirates also arose out of a kind of fragmentation, as the Barbary states were weakly controlled vassals of larger Muslim states (most notably from the 1500s on, the Ottoman Empire). To greatly simplify, initially European (and later, American) states found it most expedient to simply pay off these states, but as the balance of power shifted in their favor in the 1800s, they shifted towards coercion. The United States famously ended most Barbary raiding of its commerce with the Second Barbary War (1815), a major achievement for its young navy, with Britain and the Netherlands following suit the next year with the Bombardment of Algiers (1816). Once again the ultimate resolution came when naval powers were able to demonstrate their ability not just to strike pirate ships but to project power inland either by bombardment or the landing of troops. It is the ability to shut down the bases which suppresses piracy successfully in the long term.

Now alongside pirates, states and other larger polities can also be a problem for maritime trade if they sit on major choke-points. As you can see on the trade-route map below, most trade moves through one or more ‘choke points’ – narrow sea passages where alternative routes are either much longer or simply unavailable. Some of these are major canals (Panama, Suez) or narrow straits or channels (the English Channel, the Strait of Hormuz, the Bab el-Mandeb, the Strait of Malacca, the Öresund, the strait of Gibraltar, the Turkish straits and so on).

While most countries globally have an interest in relatively free movement through these shipping channels, the countries directly on these choke-points may have an interest in extracting value from their control. The classic example of this is the Sound Tolls, the toll that Denmark extracted from ships passing the Öresund until 1857, which at points made up the majority of the Danish state’s revenue. While any one such ‘closed’ or tolled strait may be little more than an inconvenience globally (although notice just how much of an inconvenience restricts on the Strait of Hormuz have been!), because nearly all shipping moves through at least one if not more of these choke-points, if other countries were to follow suit and every country on a choke-point tried to maximize extraction off of it, the result would be a major drop in global trade, which, as discussed above, would lead to a sharp decline in living standards in rich and poor countries alike. Everyone would be worse off.

The current global system, which assumes freedom of navigation in nearly all of these waterways and only allows fees to be charged to the degree that ships require active assistance to navigate a given choke-point (canals have to be maintained and some straits – though not the Hormuz – are narrow enough that safe passage requires help (‘pilotage’); the Turkish straits are the classic example of the latter) is largely a product of the 1800s eventually codified in the 1982 United Nations Convention of the Law of the Sea (UNCLOS), a result of imperial maritime powers (first Britain, later the United States) twisting arms in order to establish a global standard of “innocent passage.” That said, this standard was always backed up, implicitly or explicitly, by force: countries agreed to these limitations in part because everyone understood that if they didn’t, the imperial powers would make them because those imperial powers relied heavily on the free movement of goods and people over the water.

And we should be clear here: that this state of affairs – few-to-no pirates, open choke-points – benefited humanity as a whole was for the most part a happy side benefit of imperial maritime powers (initially mostly Britain, then later the United States and Britain, then later mostly the United States) pursuing their own interests. I want to stress that very clearly for any ‘America First’ers still sticking around: while this system benefits most people globally, we built this system because it benefits us in particular. As we’re going to see in a moment when we get to blockades, we wrote the rules to favor us, to favor the kind of naval power we have and the kind of trade we engage in.

But maintaining and enforcing those rules remains reliant on naval power or more correctly it remains reliant on a certain specific kind of naval power.

Power Projection Navies

The distinction I want to draw here is the specific subset of navies able to project power over the oceans. Navies, after all, come in different sorts. One distinction you will hear quite often is between a blue water navy (a navy capable of operations on the oceans, the ‘high seas’) and a ‘brown water navy’ (which only operates along the rivers and coastlines of its country) or ‘green water navy’ (not capable of global projection, but able to push out into local oceans and seas). But not all blue water navies are made equal either.

As noted above, effectively suppressing piracy long-term generally requires the ability not merely to get to the body of water in question, but to have the ability to project power ashore, because the ultimate piracy suppression requires removing the coastal bases that pirates operate on. Likewise, the kind of coercion that can compel potentially truculent countries sitting on maritime choke-points to allow unhindered traffic generally also requires the ability to project power ashore. It isn’t enough to threaten to sink that country’s navy (especially if they don’t have much of one), you need to be able to threaten to bombard key cities or deliver a seaborne invasion (we’ll come back to why this is such a problem in the Strait of Hormuz in a moment).

Since trade is global, maintaining global maritime networks means we either need one navy with global projection (which is generally how this works) or a consortium of regional navies that maintain these capabilities in their neighborhood. In practice for the last few centuries, relying on one or a few big navies with global projection has been the norm.

So we need a navy capable of global projection, which includes the ability to get to any key choke-point. It has to, once on station, be able not only to defend itself against other ships but also project power ashore. Since projecting power ashore is a process that invariably takes time it also needs to be able to sustain itself at any key choke-point.

The first requirement alone actually already rules out most of the world’s navies: only a handful of relatively large, relatively wealthy countries maintain navies with a significant number of large warships (generally destroyers and bigger) that can actually do oceanic operations on the regular. Most smaller countries instead operate a mix of smaller frigates, corvettes and cutters which are perfectly serviceable for defending and policing their own territorial waters, but are not suitable for long distance operations. You can actually see this distinction with remarkable clarity because the United States doesn’t operate just one navy – it operates two: the US Coast Guard would, for most countries, be the navy. But for blue water operations, we’re generally going to want larger ships: both because larger ships are more capable (they can carry more weapons, munitions and supplies) but also simply because open ocean travel often demands bigger ships due to more intense weather and longer time at sea. Of course, bigger ocean-going warships are going to be more expensive (which is why countries that have no designs on creating a blue water navy tend to prefer smaller, cheaper coastal ships).

But blue water isn’t enough: we need to be able to project power ashore. Historically, the right ship for this kind of power projection has varied, but since 1945 the ship type for power projection ashore has been the aircraft carrier, particularly a fleet carrier. Many navies operate smaller carriers that mostly carry helicopters and maybe a handful of vertical take-off-and-landing (VTOL) platforms, but if you want to actually project power ashore, you need a large airwing of full-sized capable fixed-wing aircraft. You can actually see this distinction in the US Navy as well. When we say ‘the United States has 11 aircraft carriers’ we’re only counting the CVNs, the fleet carriers. The United States also maintains a bunch of amphibious warfare ships – 2 America-class LHA (landing helicopter assault) and 7 Wasp-class LHD (landing helicopter dock) – which in any other navy would be treated as aircraft carriers, given that they can both operate fixed-wing aircraft. But while these ships exist to support amphibious operations, you wouldn’t want to rely on them exclusively to project air power, especially against an enemy who can actually shoot back. You want the much larger air wing of a CVN (40+ strike aircraft, as compared to half a dozen on an LHA/LHD).

Now there has been a lot of chatter lately about if aircraft carriers are actually obsolete, most of it being about the ways in which modern anti-ship missiles make aircraft carriers vulnerable. But aircraft carriers have always been vulnerable – look how many of them the RN, USN and IJN lost in WWII! The question is not ‘is the carrier vulnerable?’ but ‘what role does the carrier serve and can any other ship perform it?’ And the answer is that a (fleet) carrier is the striking arm of a fleet, able to project a lot of combat power out a long distance and no, no other ship is able to do that. Yes, you can throw missiles out of VLS (vertical launch system) cells on a destroyer or a frigate, but you are quite limited as to how many of those missiles you can carry and missiles are a lot more expensive than bombs. A carrier can, over time, output a lot more ‘boom’ at a lot greater distance using its air wing (while its air wing also protects the fleet as well).

And that’s really relevant for us because we’re interesting in projecting a lot of combat power ashore, often while keeping our vulnerable ships reasonably far away from any coastal weapons. The big carrier is the sine qua non of doing this sustainably over a long period, which is why countries continue to build them: China’s People’s Liberation Army Navy (PLAN) certainly doesn’t think that carriers are obsolete! A carrier thus is the modern form of a ship doing shore bombardment – able to throw a lot of boom at coastal (and inland) targets – and also required if you intend to actually put troops on land (where they will require both air cover and air support).

A carrier thus makes the threat to drop the marines (US Marines, Royal Marines, etc.) on someone credible. Of course you also need marines available to be dropped and the shipping and landing infrastructure to get them to the theater and onto land. The US Navy does this via the combination of Marine Expeditionary Unit (MEU) with a Expeditionary Strike Group (ESG); the former being what you are putting ashore and the latter being the ships to support doing so. Prior to that, of course, this task was done by the British; as Lord Edward Grey famously put it, “the British army should be a projectile to be fired by the Royal Navy.”

Of course, once you have that fleet, capable of moving to any given choke-point or sea lane and projecting power (including power ashore), you also need to be able to potentially sustain it there, keeping ships in supply and rotating them as necessary to maintain a continual presence until those operations ashore are complete. And that requires more than just ships, it requires a global network of logistics bases. In the Age of Steam, these were coaling stations – places where a navy could stockpile coal and other necessary supplies to resupply fleets. Of course, one coaling station wasn’t enough, you needed a connected network of them so ships traveling to distant oceans could sail from one station to the next, refilling their coal bunkers at each point. The British, of course, maintained the most expensive such network in the late 1800s and early 1900s, enabling the royal navy to operate in effectively any ocean.

During the 1900s, the United States undertook to set up a similar network and indeed one of the exercises I sometimes do with my students is noting how neatly many of the United States’ key naval bases parallel neatly the older British network, with the United States in some cases sharing or taking over the exact bases the Royal Navy had once used. That network of bases let you run supplies short distances to your fleet on station, rather than having to do shuttle runs all the way from the home country or – worse yet – be in a situation where the fleet only has the supplies it can bring with it when it departs, operating with a fixed ‘timer’ for its operations.

That said, the problem of logistics combined with how big full-sized carriers (even sub-super-carrier) are brings in another implication: you probably want nuclear-powered carriers. Fuel is one of the largest logistics needs for a fleet that is on the move or actively doing an operation and these ships need a lot of it. But the thing is, for a carrier-centered task force, the carrier is probably at least half of the total displacement of the force. A USN carrier strike group (CSG)’s displacement is around 100,000 tons of carrier, around 40,000 tons of surface ship and around 20,000 tons of submarine. The carrier and the submarines are nuclear powered, so the force is roughly 75% nuclear by weight. The advantage here is that on a practical, operational scale, nuclear carriers and submarines can operate almost indefinitely without refueling. You will run out of munitions, out of food, out of sailor’s sanity long before you need to change out the reactor fuel. Having your carriers be nucleared powered is really expensive (it requires a large body of trained nuclear technicians and engineers), but it makes global power projection much easier.

What those ingredients – a blue water navy with power-projection assets (read: carriers and amphibious warfare capability) supported by a network of logistics bases allowing them to operate globally – what those ingredients let you do is threaten force on anyone who would close down the global shipping lanes (closures that would, to be clear, violate international law under UNCLOS). Historically speaking, once this hammer is in hand, while it may have to be demonstrated form time to time, for the most part it exists as latent force. If you are doing it right, your navy should not actually be doing a lot of fighting, because everyone involved should understand you would drop the hammer if they made you, so they don’t make you.

It’s deterrence, but using a conventional military force (a navy) rather than nuclear weapons.

So if we want to stand back for a moment, we can say one of the main purposes of large power-projection navies is to deter disruptions to shipping. It isn’t their only purpose, of course, but it is perhaps their chief purpose.

The Unique Role of the United States Navy

So to recap before moving forward: global trade is essential for providing for modern living standards and most of that trade must move by sea. Sea lanes do not keep themselves open, historically they must by kept open, typically by a particular form of naval power, which I’ve termed a ‘power projection’ navy – one which is able to logistically sustain itself at long distances and project combat power ashore (via bombardment, air strikes and landing troops).

Doing that mission, in turn requires a navy that has a substantial supply of larger surface warships (destroyers, cruisers, as opposed to corvettes, cutters and frigates), as well as larger aircraft carriers (which provide the modern shore strike capability), supported by a robust global network of supply bases. Since no country maintains a worldwide colonial empire anymore, that robust global network of bases has to be predicated on a robust global network of allies and security partners.

And I’ll cut to the chase: at present, only the United States Navy can do this. No other country is even really on the verge of doing it, though one country may be moving in that general direction.

The first angle we can think about this through, of course, is power projection assets, which is to say, “which countries have fleet carriers, anyway?” Not very many, it turns out. The People’s Republic of China currently has three aircraft carriers, all diesel based; a fourth, rumored to be nuclear-powered and super-carrier sized, is on the way. The United Kingdom maintains two fleet carriers (the Queen Elizabeth class), which are fairly large and robust, but diesel powered. France has the Charles de Gaulle, the only other large nuclear-powered carrier deployed globally outside of the United States navy.

After that, the pickings get slim quick. India has a pair of diesel-powered carriers, but they’re both quite small. Russia had a diesel powered carrier, which it did use for power projection in the Syrian Civil War, but the Kuznetsov is both not a very good carrier and also has been inoperative and in need of repairs for almost a decade now. Then we have navies which operate some small carriers that are basically on the scale of a USN LHD or LHA: Italy and Japan have two each, Spain has one. Frankly, all of the carriers in this paragraph are too small to do serious power projection on their own (the Kuznetsov’s Mediterranean operations were in support of the former Syrian Assad regime, which also offered the Russians land bases). They can enhance a fleet which already includes a powerful air component (indeed, this is a key part of the mission for the smaller NATO carriers – they can assume that in a big operation, they’ll have a friendly Nimitz, Ford, Queen Lizzie or Chuck d’G to support), but they cannot offer the necessary combat power on their own.

When the current crisis in the Hormuz began, I saw people asking why European or Chinese navies didn’t intervene to keep the shipping lanes open, especially given that it was their oil being blocked. And the answer here is quite simple: they couldn’t. It is one thing to have a military capability at home. It is something very different to be able to project that power overseas and right now the only country that has a full suite of power projection assets is the United States.

We’ve already discussed above the limitations imposed by non-nuclear-powered carriers: maintaining them at sea for long periods is a lot more logistically intensive, which is why countries that think they might be doing power projection missions with carriers tend to at least think really hard about having them be nuclear powered. That said, the travails of the Royal Navy really speak to how hard this is to do – and why so few small countries do it. Maintaining a bespoke military nuclear program that can design and maintain a meaningful number of compact nuclear reactors is no small task. For four decades the Royal Navy has struggled to actually decommission old nuclear-powered submarines⁶ in part because they have a hard time getting enough nuclear technicians to supervise removing and safely disposing of the reactors in them.

The United States Navy pours a tremendous amount of resources into training nuclear propulsion specialists. Indeed, this is something I’ve interacted with directly, because I teach at a university that has both a Navy ROTC program and a research reactor. When I taught US Naval History, required by the NROTC program, a lot (more than half, I think) of my NROTC students were nuclear engineering majors. Smaller countries are simply going to struggle to generate enough nuclear technicians and engineers to sustain such a program without a huge, dedicated national effort.

Nevertheless, not (currently) having nuclear-powered carriers puts meaningful limits on China and the UK’s ability to employ their carriers on power projection missions. That, of course, interacts with the systems of global basing. Here, I think China’s experience in anti-piracy operations off of Somalia is actually really instructive. The PLAN has been sending task forces to operate in the Gulf of Aden since 2008 when the issues there became acute. But despite the fact that there are signs that the People’s Republic of China is trying to assemble a network of bases through the Indian Ocean (termed by western analysts a ‘string of pearls’), the structure of PLAN missions was pretty consistent: each force was one frigate, one destroyer and one supply ship. Each mission lasts about 180 days, including travel time from China, time on station and the return trip.

That short duration is pretty striking, because the c. 15,000 ton displacement (not including the support ship) PLAN squadrons here have roughly the same amount of support ship (one ship, in the 20,000 tons displacement range) as many American carrier strike groups (as noted above, a CSG is 160,000 tons displacement – ten times the size; it has far more combat power), but these exercises remain small and comparatively short. The suspicion one has is that what is happening here is that each of these squadrons is leaving the Chinese mainland with most of the supplies they are going to get on their one supply ship (which represents more than half of the total displacement of the squadron!) and so they have to transit all the way back home when that runs out. There is a Chinese naval base in Djibouti that must also be playing a key logistics role here, but the short duration and small size of the PLAN forces really is suggestive of the approach here. This approach, of course, is hardly sufficient to allow the PLAN to deploy basically anything in the Atlantic or Eastern Pacific or basically anywhere except the west Pacific and Indian Ocean.

At that scale, for the PLAN to deploy the combat-power equivalent of an American CSG to the western Indian Ocean (which, because their flight decks are smaller, would require basically all of them) would probably require nearly the entire PLAN logistics fleet and strain PLAN logistics such that the fleet couldn’t be kept there long and would be very vulnerable if it did not accomplish its objective very rapidly. In naval warfare, you do not want to be caught in a fight at the ragged end of your logistics tether with low fuel or munitions.

Now the PLAN apparently is building a nuclear-powered carrier. They are trying to begin setting up networks of logistics bases. That suggests at least some interest in the PRC in moving towards a global power projection navy, though I would note that history is replete with countries that started to invest in that kind of navy only to revert back to regional defense navies when it became clear just how jaw-droppingly expensive such a navy would be. In either case naval strategy is built strategy and the PLAN probably has at least a decade to go before they have the rudiments of a truly global power projection navy, even if they steamed there at full speed.

Which brings us to a key conclusion: at present, only the United States Navy is capable of performing the kind of power projection which sustained maritime commerce and at present, no other navy is particularly close to being able to replicate that capability. The two most obvious candidates to replace the United States would presumably be China or some kind of combined EU Navy, but it is not clear that China is actually interested in maintaining global maritime commerce beyond their own and a combined EU Navy on the USN’s scale would face tremendous political and economic hurdles, to say the least.

For now, the United States Navy is the only game in town.

Which, it turns out, may be a problem.

Implications

You may have noticed that the infrastructure of global maritime security is fraying lately. Indeed, I would argue, it has been fraying for quite some time.

Although establishing a direct causation is impossible, the fact that the beginnings of these issues correlate to the point at which the United States’ Global War on Terror began to go south and thus the American public began (understandably) decisively souring on America’s traditional role as the guarantor of the global system does not seem like an accident.⁷ Instead, it has led to the current baleful condition where in the United States is the only state capable of actually sustaining the global maritime system but at the same time is anywhere from indifferent to actively hostile to it.

The earliest of the current woes back back to the mid-aughts with the rise of piracy off of the coast of Somalia. That piracy intensified dramatically in 2008 and 2009, though by 2013 or so a robust international effort had largely clamped down on pirate activity. Starting in 2023, however, the United States was not able to fully restore shipping through the Bab-el-Mandeb, a crucial maritime choke-point (it’s where traffic moving through the Suez and the Red Sea gets to the Indian Ocean). Traditionally, the American response – all the way since the First Barbary War (1801-1805) to a state (and the Houthis are, in practice, the government of large parts of Yemen) disrupting its shipping in this manner would be to invade and topple that regime. Instead, for very obvious reasons, the political will to land the marines in Yemen simply didn’t exist, so the response was instead Operation Prosperity Guardian, an effort to accomplish the mission through ship defense and air strikes.

Then, of course, early in 2026, the United States started a major regional war with Iran which resulted in the closure of the Strait of Hormuz. What is striking about this decision is that deciding to go to war with Iran required disregarding freedom of navigation – traditionally an overriding American strategic interest – as unimportant. Of course some of that was simply because the war’s planners – being dumb as hell – assumed they would accomplish a quick and easy victory. But equally it is hard not to notice that the decision to disregard freedom of navigation – at least until the oil price spike reminded everyone why it was important – came from an administration that is also the first American presidency to be openly hostile to global trade since the 1930s. Moreover, once again the political will in the United States for ground operations which might restore trade simply does not exist.⁸

I want to note something actually quite important here: the war in Iran does not represent a failure of US maritime deterrence, but an abandonment of it. Prior to the decision to launch a massive decapitation and regime-change strike on the Iranian Regime, the United States was deterring Iran from doing the very obvious thing and using its geographic leverage over the strait as a tool against its regional rivals (the Arab Gulf states). The Iranian Regime operated under the quite reasonable conclusion that if it did try to shut down shipping in that region, the United States might respond with overwhelming strikes, perhaps aimed at regime change. That threat was sufficient to achieve deterrence.

The problem, of course is that once you do those attacks anyway they no longer have deterrence value: you cannot threaten someone with something you are already doing. You especially cannot threaten someone with a bullet you have already fired and cannot fire again. Once the Iranian Regime was placed in an existential (for it) war, they had no reason not to close the strait or assert their control over it and so of course they promptly did so. Iran didn’t decide it could ‘take’ the American retaliation and thus decide to close the straight, it realized it was already taking the maximum American retaliation and so would pay no greater cost for closing the strait. The United States, in attempting regime change in Iran abandoned its maritime deterrence.

But the crisis in the Strait of Hormuz isn’t even the only current maritime crisis. There have also been renewed attacks on shipping in the Bab-el-Mandeb but even more than this, Putin’s War in Ukraine has taken dramatically to the waves with Ukrainian efforts to shut down Russian exports to strangle the Russian war economy and Russian retaliation. While Iranian disruptions of shipping in the Strait of Hormuz have involved striking a few ships here or there (adding up to more the 70 such attacks since the war began), Ukraine is operating on a much larger scale, having struck more than 200 ships in just a couple of months.

The United States is retrenching and in some cases is even becoming actively hostile to the global international order. Consequently, every other country in the world must confront the possibility of a future in which the United States Navy does not guarantee the global maritime system. In the period from 1914 to 1945, as Great Britain increasingly found that it lacks the economic resources to maintain its role as the global guarantor of that system, the United States was both ready and willing to act, first as a partner (from 1918 to 1945) and eventually as the primary guarantor. There was a country to pass the baton to.

What the above analysis is meant, in part, to show is that there is no country to pass the baton to now, nor does one appear likely to emerge soon. The PLAN is, as noted, likely many years away from being able to pick of the mantle, but more to the point it is not clear that the PRC is interested in doing so. The PRC’s policy in its nearer seas has not been ‘a rising tide lifts all boats,’ but a mix of dominance politics and beggar-thy-neighbor revanchism. When disaster strikes coastlines, the United States Navy has, historically, been a key player in humanitarian relief efforts, the PLAN much less so. When in 2013 a major typhoon hit the Philippines, the United States sent $37m in disaster relief and a humanitarian relief force that included numerous ships including a complete carrier-strike group. Those fleet carriers are useful for projecting firepower ashore, but they’re also really useful for delivering humanitarian aid in conditions where ports, roads and railroads may be inoperative. By comparison, the PRC sent $200,000 and one hospital ship.

The thing is, there is no way to build a power-projection navy quickly and there really is no way to build it cheaply. Modern warships take time to build and cost a lot of money and effectively projecting power globally hinges on the most expensive and difficult to build platforms. Starting a naval buildup from nothing is not too hard – because you are not carrying the running costs of existing ships – but that stops being the case as your fleet expands. The United States Navy costs on the order of $230-280bn per year. Another country might do it cheaper, but even something like half that cost would require even the wealthiest countries to massively increase their military budget. China may be building up to this kind of navy, but they are years (probably decades) away and likely would need to expand their capital ship fleet something like three-fold, which is hardly a trivial expense.

But as we’ve established, the United States Navy is effectively a load-bearing component of the global economy. While obviously not all trade would cease if the United States dissembled its fleets, the crisis in Hormuz seems to make it fairly clear that maritime trade would be both reduced and quite a bit more expensive. And the economics of long-distance bulk transport mean that land- and air-based options simply cannot replace maritime shipping. If the trade lanes are not kept open, they may not close completely, but history suggests they will narrow.

One counter-argument here is to assert that, unlike in previous centuries, there simply aren’t enough states on major choke-points with an incentive to close them down to make this a problem. I think the last few years have thrown up considerable challenges to this notion, as we see states and non-state actors doing exactly that in the Black Sea, the Red Sea, the Indian Ocean and the Persian Gulf – and regional powers unable to resolve the problem. As we saw above, that is the normal historical pattern, slowly reasserting itself and I think, if American retrenchment continues, we ought to expect that to continue.

Now of course even in that future, global trade doesn’t simply stop altogether. It simply becomes more constrained, more limited and more expensive. Some goods become less available, ships have to take the long way around or pay expensive tolls, perhaps in some areas they have to mount greater security precautions and all of those costs get passed to the consumer. Armed merchantmen were common in some periods of history, but it is worth noting that arming merchant ships has never been sufficient to fully protect a merchant marine, for the obvious reason that the defending country must split their defenses across their many, many ships whereas the pirates or rogue states may concentrate all of their force on a single ship of their choosing.

In that world of constrained global trade, we wouldn’t expect some apocalyptic total economic collapse. But some goods that are commonly available – out-of-season or out-of-climate fruit, for instance – might mostly vanish from store shelves. Goods in advanced economies would become more expensive and living standards would decline, as wealthy countries would – on the margin – have to ‘on-shore’ low value-added industries which would pay worse wages, while at the same time the products themselves (imported or domestically made) got more expensive. Autarky – the effort to make most or all of a country’s needed goods domestically – is and always will be a losing economic strategy, because it forgoes competitive advantage. But a marked increase in the cost of trade, a reduction in the availability of imported goods will push wealthy countries in that direction and their economic growth will slow as a result.

What is inconvenient for rich countries, however, will arrive as catastrophe to poor countries who, as noted above, will find their opportunities for development curtailed and their access to affordable necessities limited.

Thus my assessment is that the American voter is making a terrible mistake. On the waves, there is at present no alternative to American naval power and the result of its absence will be a poorer United States. Indeed, Americans are right now living through a small taste of what that world looks like, as the current administration’s decision to abandon freedom of navigation as a priority brings almost immediate karma in the form of higher prices for crude oil, diesel and gasoline.⁹ Of course a lot of oil has been re-routed around the blockage in Hormuz either via pipelines or sneaking it through via ship-to-ship transfers, but all of that entails additional costs which raises prices.

The problem, of course, is that it has taken me 10,000 words to walk through why this is so – why global trade matters, why specifically maritime trade matters, what the USN’s role in that is and why we cannot simply easily ‘burden shift’ to another country. And the median voter does not have the time in their day to take in a 10,000 word lecture on naval strategy and economics. This was always a policy that relied upon the unified commitment of the elite, for the folks actually running these things to present a collective understanding to their voters that these capabilities were essential.¹⁰ Although the facts on the ground have not meaningfully changed, that elite consensus has broken and so here we are.

It is worth remembering that a worse, poorer world is possible, so that we do not become its authors.

1. Which is fine. Mahan is very focused on the benefits sea power can bring one country (the one that has it) and much less interested in the idea that sea power can provide a collective benefit to most or all countries, but it is the latter question I am focused on here.
2. The standard statistic here that I’ve seen is ‘trade openness’ which is imports and exports combined as a measure of global GDP. But for the question of ‘how much global GDP are goods moving country-to-country, that counts each transaction twice (once as an import and once as an export) so we have to halve the figure.
3. American GDP contracted by 30% during the Great Depression, so you could also say, “it would be like the Great Depression in the United States.” Those were, I recall being told often by my grandparents who were kids at the time, not the best of times.
4. And of course the existence of a British Empire was a meaningful factor in that.
5. Or, in some cases, services, enabled by modern information technology.
6. Nuclear power provides even more benefit to submarines than to carriers (you can keep a nuclear powered submarine submerged for very long periods of time, while moving at full speed), which is why you see countries that have nuclear-powered submarines but not nuclear-powered carriers
7. I’d be remiss if I didn’t note that there’s a good argument to make that the War in Iraq (2003-2011) also represents an abandonment of the United States’ global role, but that is a sticky question for another day. What matters here is that perceived failure in the GWOT is very specifically and explicitly a foundation of the current ‘America First’ movement which evidently isn’t against intervention per se, but is against intervention to uphold the Status Quo global order.
8. To be clear, reasonably so, I would argue (and indeed, have argued). Such operations would be enormously costly in both blood and treasure. Instead, a United States truly committed to freedom of navigation would have judged that whatever was to be gained by a war with Iran (not much, in the event) was not worth the disruption to that key strategic interest.
9. As an aside, while politicians focus a lot on gas prices – the distillate that people feel hitting their wallet – in the long term diesel is a bigger deal. Everything in your local store required diesel to get from a warehouse to the shelf (via a truck). Higher diesel prices thus push up the price of basically everything a little bit.
10. To expand briefly: voters quite reasonably do not have time to be educated on every issue. They take their cues from their elites, from the political and cultural leaders who they understand to have a similar worldview as their own. If the political elites all seem to accept something, the public will generally accept that as true (that’s why it is so useful to be able to present things as ‘bipartisan’ in the United States). But you lose that ‘accepted reality’ if one set of political elites disagrees, as we’ve seen with issues like vaccine and climate change where there is no real doubt about the facts, but the public thinks there is, because the political system acts like there is. The same is true here and honestly the problem is that maritime security and gains through trade are so counter-intuitive to many folks that holding a political consensus to spend two hundred billion dollars a year – even though that spending is probably a net gain for Americans – seems very difficult indeed.