Book Notes: Seapower States
Full title: Seapower States: Maritime Culture, Continental Empires and the Conflict that Made the Modern World
Author: Andrew Lambert, Laughton Professor of Naval History in the Department of War Studies at King's College, Fellow of the Royal Historical Society (FRHistS)
Publisher: Yale University Press
Amazon link to buy
My Rating: 10/10
What a fantastic book! Seapower is a fascinating lens through which we can view history. With his treatment of five different seapower states, Andrew Lambert offers us a fresh look on societies like Athens and Venice that we thought we knew well — newsflash: without considering seapower, we don’t. The work is replete with lessons on elite culture, statecraft, warfare, geopolitics, and more. I enjoyed every bit of it, and for that reason, curating notes took longer than usual. Strong recommendation.
First: A Few Definitions
Seapower versus Sea Power (definitions from the glossary)
Seapower - an identity consciously created by medium-sized powers attempt to exploit the asymmetric strategic and economic advantages of maritime power, to enable them to act as great powers. Key indicators of this aspiration include the development of oligarchic and republican political models that empower the commercial elite, focusing on naval forces rather than land forces, developing a culture suffused with the sea, and distinctively divergent from land-based models. It is a constructed identity, requiring endless repetition and reassertion...
Sea power - the strategic advantage gained by dominating the ocean with superior naval force... It can be held by any state or coalition with the requisite resources and political will.
The Persian Empire was a Sea Power but not a cultural Seapower.
Athens was a cultural Seapower that developed impressive Sea Power.
Persia had a significantly larger navy than Athens, but it served only one purpose: to project the power of the continental empire into the Mediterranean. There was certainly no cultural connection between seafaring and Persian politics. It was a river-based agricultural theocracy, like the Mesopotamian cultures that preceded it, as well as Pharaonic Egypt.
In Athens, by contrast, civic institutions were consciously modeled to support Seapower (i.e. maritime culture) and the development of Sea Power (i.e. a navy). Athens could not fight the Persians except by sea. It could not be much bigger than a City without Seapower. And yet small Athens became a feared power in the Mediterranean.
Seapower is a constructed identity. Sea Power is a measurable kinetic quality.
Seapower is highly correlated with open, inclusive political systems; Sea Power is not. I.e. any political system — democracy, dictatorship, oligarchy — can raise a navy (sea power), but democracies and other forms of open government are more likely to have seapower cultures. It’s worth emphasizing that democracy is not the only form of “inclusive” government. Hardly!
At the end of this post, I’ve included Lambert’s appendix, which is a comprehensive list of what cultural seapowers are and what they do.
Lambert focuses on five seapower states: Athens, Carthage, Venice, the Dutch Republic, and England. So below, I’ll offer a bit of summary and commentary on each one. Describing a few key elements will be a good structure. Those will be Origin, Characteristics, and Decline.
Athens is best known for creating the first major democracy, but as Lambert points out, it was also the first major cultural seapower. Athens’ seapower transformation was deeply connected to its democratic structure, as well as the leadership of men like Themistocles and Pericles.
If you’ve read Homer’s Iliad or Odyssey, you’ll be familiar with the Greek archetype of the mariner hero. The sea in Homer is majestic, though dangerous as well. But the possibility of marine heroism, adventure, and perseverance constitutes a strong cultural basis for Athenian seapower.
It was not, however, an exclusive view. Plato, not by coincidence also opposed to Athenian democracy, gives us the alternative view on the sea, one of distrust and suspicion. In book four of the Laws, he describes the character of a port city:
For the sea is, in very truth, “a right briny and bitter neighbor,” although there is sweetness in its proximity for the uses of daily life; for by filling the markets of the city with foreign merchandise and retail trading, and breeding in men's souls knavish and tricky ways, it renders the city faithless and loveless, not to itself only, but to the rest of the world as well.
Republican Rome, as we shall see shortly, adopted the Platonic view. But democratic Athens did not. It willfully cultivated cultural seapower and actual sea power as a means to resist the threat from Persia. The success of this program is exemplified in the naval victory at Salamis.
The victory against Persia gave Athens the ambition to act larger than it was, a requisite factor in becoming a seapower.
Civic art and architecture commemorated this choice. The victorious Athenians built statues, temples, and coastal infrastructure.
The high costs of maintaining a fleet of trireme boats meant that Athens had to pursue empire as an economic measure.
Seapower culture and the professional navy allowed small Athens to act as a great power, feared by its neighbors.
Athens became overextended, and the first real naval losses during its time as a seapower led to a cascade. Once Athens had enjoyed the benefits of empire, it was resistant to relinquish them, which became a liability.
Seapowers cannot act as great powers permanently. A commercial sea-based state is an alternative to, not a substitute for, a land-based empire.
Athenian seapower culture actually survived defeat in the Peloponnesian war and was rekindled. Only once Philip II of Macedon destroyed the infrastructure that made seapower possible did it come to a complete end. Philip, and Alexander after him (and Napoleon Bonaparte 2000 years later) destroyed seapower from the land.
The North African city-state of Carthage was founded in the 9th century B.C. by Phoenician sailor-settlers as an outpost to facilitate Mediterranean trade from Tyre, in what is now Lebanon.
Its government had an Assembly in which citizens held significant power. Each year, two Suffetes or magistrates were elected to lead. It had a Senate and Constitution, which Aristotle considered successful.
It built grand civic infrastructure to accompany its seapower culture. The best example of this is the artificial circular harbor and ship sheds built of stone at the center of the city.
Carthage ended first as a seapower state, and then as an independent state entirely, at the hands of the Roman Republic. Lambert makes a very interesting commentary on the real reasons for the Roman animosity toward Carthage, especially between the Second and Third Punic Wars.
Rome did not fear sea power strategy, in any shape or form, and did not consider Carthage to be a significant military power. The fear that grew after the Second Punic War was social and political. The Senate judged seapower Carthage to be the epicentre of a levelling political tendency that threatened to destroy their class and their privileges.
The treaty that ended the Second Punic War had diminished Carthage as a power significantly; it gave up its sea empire, large parts of its navy, and its ambition. Lambert argues that the militarism of the Roman Senate guaranteed they were going to invade somewhere, so why Carthage? One reason, to quote Lambert, is that Carthage “offered [an] alternative cultural model to the wars, armies, and aggression of oligarchic Rome...”
There’s a great line in Gladiator where Senator Gracchus says, of Emperor Commodus, “I think he knows what Rome is. Rome is the mob.” Gladiator takes place in imperial — not republican — Rome, but the point stands. Carthage, with its popular Assembly and political system that could appropriately be described with the modern term “populism”, showed the autocratic Roman Senate what it looks like when the mob isn’t pacified by the state, but actually assumes control of the state.
Ergo, Carthage had to be extinguished — both the physical city, as well as the seapower culture that had allowed for the development of such a political system. And extinguished it was. The Third Punic War was not an even conflict; it was a war of extermination, the systematic destruction of a state, people, and culture, by a much more powerful enemy.
As ever, history is written by the victors, and at the close of his chapter on Carthage, Lambert makes an excellent point on the historiography of the conflict. Specifically, he argues that Roman revisionism has left us with a narrative of Carthaginian bloodthirst and “Eastern” savagery, embodied in image of the General Hannibal and his elephants in the Alps, on their way to level Rome.
Hannibal was indeed a talented general, and did invade the Italian peninsula with elephants, but Lambert says that this obscures what Hannibal really was in the grand scope of things — “a classic seapower statesmen, a cool, calculating realist with a preference for treaties and compromise” — and what he represented, which was a successful maritime state with inclusive politics.
While the wars between Rome and Carthage are often represented as a contest for dominion over the known world, in reality the two states fought for very different worldviews. The Romans sought more land, wealth, power, and control. By contrast, seapower Carthage sought a stable, balanced world in which it could secure trade routes and profit from an expanding Mediterranean economy.
One thousand years later...
Yes, it really was about 1000 years between the fall of Punic Carthage (146 B.C.) and the rise of the next real seapower State, also in the Mediterranean, around 800 A.D.
Or more formally, the Most Serene Republic of Venice, Serenissima República de Venezia.
Venice is the best example of a Seapower state whose character as such was invented, more or less, out of nothing. The Athenians had the Homeric narratives and the Minoan myths to draw on, which Thucydides and Herodotus both valorized. Each of these was deeply engrained in Greek and Aegean culture, so their adoption made sense. The Venetians, by contrast, had no such historical font to draw upon. So, they improvised!
The Venetian aristocracy consciously constructed the Republic’s Seapower identity through unique architecture, culture, tradition, and governance.
The center of Venice is an island in a lagoon, a few miles from the mainland, or the Veneto.
You could describe its politics as something like marine-mercantile statism. It was dominated by aristocratic merchants who elected a Doge as ruler for life. The Doge was more than a first-among-equals in that he had more powers than any aristocrat, but this was not a monarchy, and there were mechanisms of accountability. This was an oligarchy and a very effective political system, inclusive of multiple interests.
In the golden age of Venetian commerce, aristocrats built canal houses in the center of the city and lived on the upper floors. The lower level, however, was always reserved for commercial activity, reflecting the elite participation in the defining institution of the city.
Culturally, Venice had two major elements: a civic religion combining the worship of commerce, the state, and the sea; and a distinct flavor of Catholicism that was relatively free from Papal political control in Rome.
This duality was exemplified by an annual ceremony, coinciding with the Feast of the Ascension, called the Marriage of the Sea, in which the Doge would actually drop a consecrated ring from the state Barge (Bucintoro) into the sea, commemorating the everlasting marriage between it and Venice.
Venice was slowly undone by the politics of land, which corrupted its elites and destroyed the city’s maritime identity.
Venetian power peaks right before 1500, after which the state begins to decline. Part of it was just military reality, but the English politician Joseph Addison attributes the decline explicitly to a change in elite values. The elite merchants gave up on profit in exchange for mere privilege.
Venetian elites, after becoming rich through commerce, actually reject it as a virtue. And instead of continuing to participate in commerce in their wealth, the aristocrats begin to take positions in the Church and State. They close the commercial floors in their canal houses and develop large estates on the mainland, where they lounge around. Becoming a landed political class puts them at odds with the virtue of commerce on the sea that had defined their entire civilization for centuries.
Throughout the decline ~1500-1800 Venice becomes more like the cities of the Italian peninsula, and its civic architecture begins to resemble Rome, with classical orders. Venice had invented itself once already, so this transformation was easy enough.
Venice comes to an abrupt end in 1797, under the guns of Republican France. The Venetians had coasted through almost 300 years of stable decline, but as soon as a real threat — Napoleon — came knocking, the aristocrats don't resist at all, wanting to protect their new land estates.
Lambert points out the irony that in the very period that Venice reimagined itself as a new Rome, it was actually on the Carthaginian trajectory, about to fall prey to the actual new Rome, which was Republican France. The city of Venice itself was spared the physical fate of Carthage and was not razed to the ground. But Napoleon and the Austrians after him did affect a number of physical, architectural, and obviously political transformations on the city so as to neuter its Seapower culture once and for all.
That included the construction of a causeway to physically connect Venice to the mainland, which was effectively the destruction of its central geographic feature, that had made it so unique. As a result, 200 years later, most tourists arriving in Venice do so by car or train, and there’s no question that it is an Italian city.
As for boats and Seapower culture, the gondolas and water taxis carrying tourists up and down the canals seem like comical shadows of what was a unique and beautiful 1000-year maritime civilization and great power, La Serenissima.
Addendum: Genoa, the seapower that wasn’t
Genoa was also an important maritime city state in the Mediterranean, the peak power of which coincided with Venice. But Genoa — on the Ligurian Sea — did not become a seapower, nor did it achieve nearly the same success as Venice — on the Adriatic. Because of the shared geography and timing as control variables, it makes for an interesting comparison.
Genoa lacked the ambition to become a great power, and so didn’t have the type of civic rituals, artwork, and public display that was integral in Venetian life.
Genoese elites prioritized one thing above everything else: freedom from taxation. The resulting lack of any powerful state institutions made for an almost anarchic, libertarian polity. Lambert describes Genoa as an “anti-state, relying on private wealth, private naval forces, and mercenary troops.”
Genoese elites, instead of promoting their city and themselves to the world, fought pettily amongst one another. Lambert has a great line: “They created no images of themselves.”
Genoese bankers, merchants, and even sailors became dependent on larger states for opportunities. The classic example of this is Christopher Columbus, whose middling career in Genoa was saved by the patronage of a continental monarch, Ferdinand II of Aragon.
With that incentive structure, and no grand institutions of state for Genoese to serve, it’s no surprise the city atrophied. As with Venice, Genoa is a story of elite decision and elite action; or rather, elite indecision and inaction. And that’s a world of difference.
The Dutch Republic
The 16th century Dutch Revolt against Habsburg Spain (a powerful, monarchic autocracy) resulted in the formation of the Dutch Republic. It was a somewhat slow process, defined by the push and pull between a group of semi-royal Princes (Stadholders and the House of Orange) and the capitalist aristocrats of Amsterdam. The latter group eventually won out, winning an open aristocratic political system that prioritized securing peaceful commerce by raising a navy.
In 1650, the position of Stadholder (a dominant military figure within the Republic) is eliminated and seapower consciously adopted as a national policy. But the Dutch Republic as a true seapower in Lambert’s sense of the word lasts only about twenty years, 1653 to 1672.
The Seapower State emerges in the context of Amsterdam developing itself as a maritime city-state, akin to a Venice of the North.
The Dutch Republic’s Navy reflected the deeply capitalist society in which it was raised. It was highly meritocratic, with patricians competing for prestige within it. It was managed by regional and local admiralty councils, the members of which had experience in seaborne commerce. These committees had a strong profit motive for strategic success; and succeed they did. The most successful admirals didn’t just become rich — they became public heroes.
In contrast to the public cult of navy heroes, the Dutch land army was not valorized. An army was viewed as a necessary defense against continental enemies, but one that could also threaten Dutch liberty. It was treated with suspicion.
The Dutch were great shipbuilders, but they never built “prestige ships” like the English, Danish, and Swedish monarchies did. The Dutch weren’t interested in dominating the seas as an expression of monarchic power; they wanted to secure commerce.
The Dutch State, dominated by Amsterdam, was more effective than any autocracy at mobilizing resources. Taxes were high but not unpopular due to the agency that the merchants paying the taxes had within the system. They could direct state resources effectively to support commerce, which gave legitimacy to the tax levels.
Interest rates were lower than other powers.
The Dutch Seapower state — the “True Freedom” regime — was abandoned in response to a French land invasion in 1672. The Dutch had successfully resisted the much larger English naval force in the 2nd Anglo-Dutch War, including the humiliating English defeat at Medway. The Dutch were acting as a Great Power at sea, which was deeply provocative to both the English and French monarchies. Five years later, France and England entered into an alliance and attacked.
Not all the ships in the world could defend the southern and eastern Dutch borders against a land army, and so the Dutch shifted back to terrestrial defense. That required the restoration of a militarist system led by a Stadholder and the end of the open system dominated by merchants.
The Dutch won this third Anglo-Dutch War, but not without the loss of seapower culture. They sacrificed seapower to England in order to preserve territorial integrity. And so the Dutch Republic lost its unique character in 1672, abandoned its self imagination as a Great Power, and became just another European continental military state.
Other factors that further diminished the remnants of Dutch seapower culture after 1672:
In 1690, merchants were banned from the Amsterdam Chamber, which created a hereditary elite divorced from commerce and trade. It is not a coincidence that this period marked the beginning of the Dutch economic decline.
The Dutch East India Company (VOC is the acronym in Dutch) began to lose money trying to maintain a marine and land monopoly half a world away in Indonesia, which was prohibitively expensive. Its policy of building resource monopolies violated the cardinal rule of a Seapower: to increase total commerce and benefit from it, while protecting your own. Dominion over the seas is a universal goal, incompatible with a functioning commercial state.
In order to finance an empire, you need a production base as home. The Dutch homeland relied on commerce, so making that commerce significantly more expensive by trying to pursue an expansionist and monopolist policy at the same time is a recipe for disaster. Pursuing open expansion or limited monopoly might work, but not both.
The Dutch Republic, like Venice, persisted as a state in managed decline, which Lambert describes as a conscious elite choice, much like the decision half a century earlier by merchant republicans to create a seapower state in the first place.
England moved away from continental Europe in a few key ways in the 16th century, most importantly by separating itself from the Church in Rome.
Long story short: the English destroyed the famed Spanish Armada in 1588 in a naval battle in the English Channel. The war with Spain ended indecisively with a treaty, but the defeat of the Armada made for a great foundational story of sea power upon which to construct a seapower culture. In the 17th century, English seapower stagnated due to its fundamental incompatibility with absolutist monarchy. By 1700, though, the merchant classes and the City of London had managed to partially disempower the monarch and create what was fundamentally a republican system.
A 250-year seapower state emerged.
Lambert goes as far as suggesting that the purpose of the monarchy and landed rural nobility, after about 1700, was to conceal the true seat of power in England: London. That’s not to say the monarchy was irrelevant — it remained important, especially as a symbol. English monarchs fought at sea, even into the 20th century.
Montesquieu considered Britain the modern Carthage, a commercial republic, combining a great navy with a political system controlled by the merchant class, enabling the state to access deep economic resources to sustain long wars, and an empowered citizen class.
The French compared England to Carthage as a slur — Napoleon would call them a “nation of shopkeepers” — but the English themselves didn’t take it that way. They embraced the Carthaginian identity and rejected the Platonic view of the sea held by Rome and later by France.
The sea was not just a utility to the English, or a means of defense alone. It became a national symbol, integral to collective identity. English art became obsessively focused on the sea, adopting and extending the tradition of Dutch and Flemish marine painting. It was a national effort, coordinated from the top.
After the 1776 catastrophe, the British stopped attempting to assert Roman-style administration on all its empire. What emerged is a Commonwealth.
Some places had to remain under strict imperial control — Gibraltar, Hong Kong, Singapore, Halifax, etc — in order to have a sea empire at all in a world of land empires. But the major populated colonies were mostly connected to Great Britain by common heritage, not parliamentary control. That served Britain well, and when it faced destruction twice in the 20th century, Canadian, South African, Australian, and even Indian soldiers made brave sacrifices to defend the Commonwealth and its home island.
This point reminded me of Churchill’s great 1940 speech in the House of Commons, anticipating a German invasion of Great Britain.
We shall never surrender, and even if, which I do not for a moment believe, this Island or a large part of it were subjugated and starving, then our Empire beyond the seas, armed and guarded by the British Fleet, would carry on the struggle, until, in God's good time, the New World, with all its power and might, steps forth to the rescue and the liberation of the old.
At the sunset of the British seapower state, you could destroy and occupy Great Britain and still the idea of Brittaniawould persist “beyond the seas” — it would be the boats in Victoria Harbor in Hong Kong, in Australia, in Canada, etc.
Notice also the appeal to America. Churchill knew well that while Britain might successfully resist Nazi Germany, even for decades, it needed the help of a continental military power in order to defeat it.
Lambert says that we — the United States of America, I mean — ended the British seapower state. Not through conquest, but by diminishing its naval power with treaties and economic measures. The US, especially under President Woodrow Wilson, was opposed to British imperialism, and had the power to dictate terms to effect that goal. By 1945, the terms of the US alliance with Britain had left that country nearly bankrupt, even as it was nominally intact.
And so Britain gave up its naval might and the remaining parts of its empire. The US could fulfill all of the functions of a powerful British navy at a fraction of the cost to Britain.
What strikes me about the decline of British seapower is that there is something deeply honorable about the way it went out.
If you watched the Christopher Nolan movie Dunkirk, you’ll know that when over 300,000 men of the British Expeditionary Force were cornered at the edge of continental Europe in 1940, just days from being annihilated by the Wehrmacht, it was a fleet of nearly 1000 civilian ships that managed to rescue them.
That is seapower. That’s as Anglo as it gets.
Was America a Seapower State?
No. Maybe small parts of it could have been at some point in the antebellum period, but I’d say that American state culture from the early days of the Republic was really focused on two things:
Jeffersonian physiocracy — aka “manifest destiny” aka “westward expansion.” It was important and virtuous to settle the continent and profit from it. Policy was shaped accordingly. See: the Homestead Acts, railroad laws, land grants, etc.
The Monroe Doctrine — the Americas should be free from European monarchic/imperial power. The U.S. still occupies a small sliver of Cuba because we believe this so strongly!
In some ways, these two goals are reminiscent of seapower states. And it’s easy to spot the similarities: we’ve got a strong commercial culture, an open and fairly cosmopolitan system, and we aim to facilitate trade around the world.
But fundamentally, the U.S. is a continental power. To the extent that our continental hegemony required the development of a navy and a commercial seafaring culture in certain parts of the country, the U.S. dabbled in seapower. We have the largest navy in the world, the most deep-water ports, rivers that enable maritime commerce to penetrate deep into the continent, etc.
But you’d have a hard time finding examples of deliberate statecraft oriented toward the sea that doesn’t actually serve the bigger purpose of it’s our continent and we’ll do what we want with it.
What Happened to Portugal?
Portugal is a small country that made outsized achievements in ship design and navigation in the 13th-15th centuries. The Portuguese Ferdinand Magellan was the first to circumnavigate the globe, though he did it under the Spanish flag. Its national epic, “Os Lusíadas”, is an ode to Portuguese seafaring and Vasco de Gama. So, why didn’t it reach greatness or become a real seapower?
In one sentence: Militant Catholicism and state antisemitism are bad for business.
That’s a concise way of saying that the Portuguese monarchy was most concerned with continental affairs, including appeasing the Spanish and constructing an identity of Christian chivalry. At no point were merchants empowered in state institutions, which remained fixated on royal and Papal glory. At the end of the 15th century, Portugal expelled its Jews, most of whom went to Holland. It is a beautiful historical irony that it was the Dutch East India Company — which undoubtedly employed no small number of descendants of those Jews — that eventually terminated the Portuguese imperial project in Asia.
The Portuguese empire was basically the temp-agency of Europe. Having expelled the Jews that constituted a significant part of the national brain trust, Portugal came to rely on English and Dutch sailors, and Genoese bankers, in order to be relevant at all.
The empire survived because of gold from Brazil, but it became clear that continental Portugal was the weak link. One English official actually recommended to the Portuguese crown in the late 18th century that it relocate the capital to Rio de Janeiro!
30 years later, Brazil won independence, and never looked back.
My Top Lessons
As the seapower states show, it is possible to consciously shape a state bespoke with ritual, architecture, ornament, heroes, and political structure, all oriented toward a specific telos. Today, we might view statecraft like this, undertaken without irony, as artificial. That view explains quite a bit of our lack of vitality. In modernity, irony is king.
Q: Are closed systems (e.g. continental monarchies) afraid of open systems (e.g commercial seapowers)?
A: Not necessarily. But when the latter threaten — or, to take a Girardian angle, imitate — the telos **(which is usually something like “universality”) of the former, yes. If you scare the elites of a great power, or role-play as a great power, don’t act surprised when you’re treated like one.
Q: Can your small commercial seapower actually defeat a continental empire?
A: No, probably not. So, it’s best to avoid conflict, even at a price. But sometimes defeating the larger enemy isn’t necessary, as long as you’re willing to play a different game than your opponent. But as noted in (3), imitation can lead to disaster, so be careful.
If you think being ruled by commercial elites is bad, just wait until your elites are no longer engaged in commerce and become sedentary. Then you’ll see how bad it can get.
A corollary of (4) is that when your elites abandon the founding virtues of your society — commerce or otherwise, and even if those values are based on myth — it is over. You need elite buy-in and participation in the beliefs and practices that constitute the state.
Don’t expel the Jews; you’ll regret it (though your enemies, who receive the Jews, will thank you for it)
The following list is included as an appendix at the end of Seapower States. I found it useful.
Cultural Seapowers: A Conceptual Aide-Memoire
They are consciously created ‘works of art’, following Burckhardt’s argument.
The process is national, centrally directed and reflects the shared ambitions of an oligarchic elite combining commerce and capital with land and social rank.
They emphasise maritime commerce and revenues drawn from commerce in the economic and fiscal life of the state.
They have oligarchic/progressive politics, and are culturally advanced and outward-looking.
They give the commercial classes a significant share in political power.
They prioritise naval over military power.
They enact legislation to create, secure or improve the maritime and naval resource base – be it ships, seamen, raw materials or trade routes.
They are active in suppressing piracy – which is both a hindrance to trade and the cause of higher insurance rates.
They depend on core trade routes, for which they are prepared to fight
They use naval power to protect trade, convoying merchant shipping
They are open to trade with other nations – but use economic measures to crush dangerous rivals.
They secure a limited portfolio of overseas bases, either as imperial outposts or through alliances, which provide critical logistics and strategic facilities for naval forces. These are heavily fortified, especially against attack from the land.
In war they employ limited strategies based on economic blockade – because they lack the military power to deliver a knockout blow.
In war they employ mercenaries or rely on allies, waging war on land with money, not men.
They can only operate effectively in a strategic context where several land powers exist, because:
seapowers are defeated by drawing them into large-scale existential land wars; and
they are ultimately unable to resist truly hegemonic continental powers