If patriotism, as the blowhard Samuel Johnson once said, “is the last refuge of the scoundrel,” then “the national interest” must be the first. It is the most protean of justifications: by invoking it, states can just as easily legitimize military interventions as excuse unpardonable passivity. Who hasn’t at some point heard a government official voice their sympathy with the plight of such-and-such people, only to add that it isn’t in the US national interest to do anything about it? Ubiquitous in imperialist rhetoric, the phrase “national interest” is thus no less common in speeches by louche isolationists — it means, in other words, whatever the government wants it to mean.

Tracing the United States’ rise to regional hegemony, Sean Mirski’s We May Dominate the World is a compendium of how Washington, by equating the Monroe Doctrine with the national interest, sanctified scores of military interventions in its hemisphere. The United States’ foreign policy, Mirski says, “was consistently shaped by one central, overarching challenge” — the so-called problem of order. To ensure the integrity of the Monroe Doctrine, US policymakers felt compelled to intervene “whenever one of their neighbors met three conditions: it was strategically important, it was threatened by foreign powers, and it was too unstable or otherwise weak to defend itself.” By proclaiming the entire continent strategically important, the United States prepared the way for interventions wherever European empires might land their forces.

Mirski sketches three phases of American interventionism before World War II. From 1860 to 1896, the United States responded to European incursions by seeking to strengthen neighboring countries through commerce. Prosperous neighbors, Washington hoped, could themselves guarantee their own sovereignty, though the United States was of course prepared to use force if necessary. The second — most expansionist — phase began with the Spanish-American War and lasted until the end of World War I, when US regional hegemony had been secured. The third phase saw the return of the “Good Neighbor” policy; however, that brief imperialist hiatus famously came to a close with the Cold War. That, put very simply, is the evolution of American interventionism — but what of its consequences? Theoretically, interventions were supposed to stabilize restless countries, but in practice they resulted in ever more strife:

Time and again, the United States would intervene to stabilize and strengthen its troubled neighbors; time and again, those interventions would miscarry, leading to greater instability that required new and more intrusive interventions.

It was only once the Confederacy had been vanquished that the United States could begin enforcing the Monroe Doctrine. Napoleon III of France had seized on the American Civil War to install the hapless Habsburg prince Maximilian on Mexico’s throne; in response, Washington supplied his enemies with weapons, sheltered them from French raids, and let US soldiers volunteer in Mexican president Benito Juárez’s army. Of course, Maximilian’s empire was bound to crumble sooner or later, even if the French troops had stayed or even if the United States hadn’t supported the republican side, but the episode convinced US statesmen that the Monroe Doctrine had to be upheld.

The problem, though, was that the region had lots of weak states that, in Secretary of State William Henry Seward’s words, offered “temptations which the strong cannot reasonably be expected to resist.” Therein lay the origin of Washington’s strategy to stabilize the region by trade. But by pulling its neighbors into its economic orbit, the United States created fragility rather than resilience — its neighbors became overreliant on US trade.

In the book’s perhaps most pellucid passage, Mirski illustrates how Hawaii’s sugar trade helped cause the revolution that eventually forced Washington — somewhat reluctantly — to annex it. A favorable trade treaty had incentivized Hawaii’s sugar production, so much so that sugar became by far Hawaii’s most important sector. But sugar plantations required immense capital, the sort that few indigenous could muster: thus rather than shoring up the Hawaiian monarchy, trade bolstered the white planter class while making Hawaii entirely reliant on sugar exports. Hence, Mirski writes, “when Congress changed the sugar tariff in 1890, it sent Hawai‘i spiralling into economic crisis and eventually revolution; when Congress changed the tariff back four years later, it plunged Cuba into its own economic crisis and eventually revolution.”

That kind of scrutiny of the ideological and economic factors behind American interventionism would’ve been welcome, but Mirski is convinced that in general those factors mattered little. The only interpretation of US empire that can carry the evidence, he says, is the realist, security-focused one. Of course, he concedes, “the problem of order did not cause every regional intervention,” citing the expeditions to Cuba and Panama, but “it consistently channelled American policy in one specific direction, and Washington was rarely (if ever) able to deviate from its strictures, even if other factors also pushed in the same direction.” This is to seriously risk weakening the thesis by overstatement. It would’ve been enough if Mirski had shown how “the problem of order” shaped the course of US interventionism, but instead he seeks to show its unrivaled centrality.

The so-called realist school of international relations has tended to take a sympathetic view of imperialism; Mirski, however, thinks it is “more prejudicial than probative” to call the United States’ conduct “imperialistic.” Instead, Mirski says, we ought rather to describe the US foreign-policy approach as “interventionism.” What were its causes? “From 1860 to 1945,” Mirski writes, “the United States found itself intervening time and again in its neighbors’ affairs primarily for one overriding and paradoxically defensive reason — to forestall the threat of intervention by hostile great powers.” Self-defense, rather than imperial self-interest, were the motives behind the United States’ geopolitical stance:

Logic and experience thus led American policymakers to a conclusion that seemed as tragic as it was inescapable: the safest way — sometimes the only way — to stop its rivals from filling local power vacuums was for the United States to fill them first.

Put simply, Washington had to intervene: if Washington had let the European empires take even one new colony, Mirski says, it might’ve triggered a scramble for the Americas much like the scramble for Africa:

Seeing threats everywhere was accordingly not paranoia; it was a rational response to a world full of potential dangers. That, of course, is the tragedy of great-power politics: the international system incentivizes rational actors to fear for their safety and act in ways that result in less safety — and much more violence, bloodshed, and war — for everyone.

This is the realist position stated in the clearest of terms. But to call the United States’ belligerence “rational” is the realist’s version of the view that, in W. H. Auden’s words, “History to the defeated / May say Alas but cannot help or pardon.” Mirski says that he doesn’t “intend to whitewash the United States’ conduct.” However, to claim that “Try as they might, officials in Washington could not escape the problem of order’s basic logic” is to attenuate their culpability. To paraphrase Kant: inevitability implies exoneration.

Could it really be said that the United States feared threats from European powers? Perhaps in some cases, but not generally. If there were in fact such threats that Washington simply had to intervene in, say, Nicaragua, one would’ve expected the United States to invest in a proper fleet capable of resisting a European invasion of the American mainland. But the US Navy, as Mirski himself makes clear, was laughable until the mid-1890s — and even then, it only modernized most grudgingly. What Washington feared was not European reconquest of the United States, but of European claims to its supposed “sphere of interest.” Mirski quotes Alfred Thayer Mahan’s statement that the Monroe Doctrine was motivated by “purely defensive ideas,” but that’s only to restate the cliché that offense is the best form of defense. By its very nature, the Monroe Doctrine was aggressively imperialist. Defending it meant protecting an imperial sphere.

“Rightly or wrongly, American leaders were obsessed with the great-power threat to the hemisphere,” Mirski writes. But that is not the same as saying that they were obsessed with great-power threats to the United States itself — they were not fearful of European threats to the United States but to the United States’ imperial sphere. Mirski simply takes it for granted that European powers were ready to carve up Latin America like Africa. “One of the most compelling pieces of evidence supporting the existence of a great-power threat is the extra-hemispheric control group,” he writes. That pseudoscientific phrasing illustrates what’s wrong with the field of international relations: its simplistic theorizing, its scant historical nuances:

From 1870 to 1914, Europeans seized political control over at least 85 percent of previously independent nations in Africa, the Middle East, and Asia, including China. Latin America, however, maintained its independence from Europe during that same period offering essentially identical opportunities for European expansion. One can and should question the ways in which the United States tried to safeguard the hemisphere, especially its decades-long streak of interventionism. But it is surely no coincidence that the only part of the world to survive Europe’s imperialism practically unscathed was the one region home to a jealous great power that drew the line at any foreign expansion.

When used in polemics, the term “essentially” signals that something crucial is being elided — in this case that the conditions weren’t “essentially” the same. Two things should be immediately obvious. The reason European powers weren’t carving up Latin America might simply have been because they were preoccupied elsewhere: not even the British Empire could collar the whole globe simultaneously. Latin American countries, moreover, had already been colonized: they had expelled their imperial rulers, which every European country remembered very well. Had Mirski merely said that European behavior in Africa made US policymakers more resolute in upholding the Monroe Doctrine, no one could’ve complained, but he can’t resist the overstatement.

“Man is the same in all places and in all climes,” said the Tenth Count of Aranda. The Spanish Empire, the count predicted, would eventually lose its colonies to the United States because that’s what happens “in all ages with nations that begin to rise.” “Time,” Mirski writes, “proved the Count right.” Those who believed that the United States, with its vaunted love of liberty, could resist the temptations of power were wrong. That’s one of the insights of realist theory — power counts for more than principles. Piling examples on top of each other, Mirski shows how numerous American presidents sold their principles — to my mind rather cheaply — in exchange for increasing the power of the United States. Good intentions mattered little: Grover Cleveland thought that the ouster of Queen Liliuokalani of Hawaii had been a moral outrage, but his government nevertheless collaborated with the coup makers. As a rebuke to naive liberal idealism, the realist school is indispensable.

The tragic view of human nature that the count gave voice to has something going for it, but it is rather reductive. Yes, people have, in Hans Morgenthau’s phrase, an inner animus dominandi to subjugate others, but that’s not all it is to be human. The flaw in Mirski’s kind of realism is that it’s far too simple. Dutifully conceding that “other factors” like ideology or economics might have mattered on the margins, Mirski proceeds in hasty paragraphs to minimize their role. He ends up trying to explain too much by too little. To exaggerate somewhat: it’s to view international relations as a grand game of Risk, where each empire’s sole goal is to secure hegemony. For example, he claims that “the problem of order” coupled with human imperfectability explains practically every conflict from World War I to today’s Ukraine war and the rise of China. To make such large claims for his theory, he reduces it to a banality — that instability offers opportunities for imperial expansion. But we’ve known that since Thucydides.