Indeed, inside the Beltway, virtually anyone with influence on policy now professes to be a “realist” with regard to American foreign policy towards China. Unfortunately, casually throwing around the word “realism”—often as little more than a euphemism for being “tough”—falls far short of providing a productive guide to policy. Worse, and harrowingly, the two most influential “realist” theories commonly gestured at in this context are flat wrong in their analyses and appalling in their policy prescriptions, proffering misguided and dangerous advice. The bumper-sticker notion of a “Thucydides Trap,” which suggests an inevitable clash between the United States and China, is a phrase bandied about ubiquitously at the highest levels of both governments; the theory of “offensive realism,” which insists that China must (and should) resort to war to achieve its goals, enjoys widespread currency in Beijing.
This is doubly disastrous. First, the hazards are enormous and ominous: there are few challenges more unsettling to international politics than the emergence of a new great power. China, today, is the latest in a long line of obstreperous upstarts who assert that the way the world is run should be adjusted to better account for their rising status. Similarly, the United States is hardly the first self-satisfied guardian of the status quo. Historically, these tensions have commonly been resolved by war. Second, realism has much more to offer than its current caricatures would suggest. Moreover, properly understood, it can provide a valuable guide for US policy towards China.
In this essay, I briefly explain the common tenets of realism in theory, and the follies of its most prominent advocates in practice. Specifically, realism went wrong when something called “structural realism” swallowed realism whole—to the extent that even many professionals conflate the two. I will zero in on the flaws of a pair of enormously influential structural realist approaches to contemporary Sino-American relations, each of which has been promoted assiduously by a senior scholar at a prominent institution. I take aim specifically at University of Chicago political scientist John Mearsheimer’s “theory of offensive realism” and Harvard Kennedy School professor of government Graham Allison’s notion of a “Thucydides Trap.” I will conclude with a consideration of a realism that does better—classical realism. Although on-brand wary and pessimistic, it nevertheless offers a productive (and less dangerous and self-defeating) way forward.
¤
Any realist perspective takes as its point of departure the consequences of anarchy—that is, in world politics, there is no ultimate authority to adjudicate disputes, and, worse, there is no guarantee that the behavior of others will be restrained. Countries must look out for their own survival—because no one else will. And the stakes could not be higher, as human history is littered, from the ancient past to the present day, with countless episodes of horrifying barbarism. This in turn means that states must be alert to the power and military capabilities of others.
Structural realism stops there: with states, dwelling in anarchy, understood as “like units” (like billiard balls, they may come in different colors, but they respond similarly to external stimuli), differentiated only by their relative capabilities. The analysis is thus limited to the effects of “systemic forces” generated by the interaction of states—that is, from the distribution of power and changes to it. Nothing else matters. With regard to contemporary Sino-American relations, two such approaches have been enormously influential.
Mearsheimer, in his 2001 study The Tragedy of Great Power Politics (a revised edition was issued in 2014), derives a variant of structural realism known as “offensive realism.” Allison’s 2017 book Destined for War: Can America and China Escape Thucydides’s Trap? purports to apply the analysis of Thucydides’s History of the Peloponnesian War to contemporary US–China relations. Tragedy argues that China will inevitably make a militarized bid for regional hegemony and that the United States must take dramatic measures to stifle its rise; Destined for War sounds an alarm that the two powers might stumble into a destructive war, just as the great powers of Europe did before World War I.
Both perspectives, however, are fundamentally flawed. Their errors of analysis can be traced to their dedicated structuralism, which blinds both authors to the crucial role of politics and purpose in shaping assessments of interest—and ignores the vital role played by the choices made by great powers in shaping the pattern of world politics.
¤
Mearsheimer insists that “China cannot rise peacefully.” Instead, as its capabilities increase, China will become “an aggressive state determined to achieve regional hegemony.” The inevitability of this—and this theory is so deterministic that it would make a physicist blush—means that any policy measures designed to shape the international incentives that China might face are “misguided” and “doomed to fail.” Given this, the United States should direct its foreign policy to make its implacable adversary as miserable as possible.
But Mearsheimer is wrong. Working with assumptions that are individually reasonable, he draws conclusions from them that are logically incoherent, and in turn offers dangerously (tragically?) misguided policy prescriptions. Two of offensive realism’s “bedrock assumptions” are especially relevant here. One is survival: “[S]urvival is the primary goal of great powers. Specifically, states seek to maintain their territorial integrity and the autonomy of their domestic political order.” The other is rationality: “[G]reat powers are rational actors.”
>From this, Mearsheimer argues that great powers, motivated solely to ensure their own security, will recognize that the safest position in the system is one of regional hegemony. Only a regional hegemon is secure in the knowledge that it will not be conquered by others. Thus, states that can plausibly make bids for regional hegemony will do so. “[S]tates quickly understand that the best way to ensure their survival is to be the most powerful state in the system,” Mearsheimer avers. “Only a misguided state would pass up an opportunity to be the hegemon in the system.”
But in the space between those two assertions, Mearsheimer makes a giant and illogical leap, one that drives the entire argument—and amounts to its irretrievable and fatal flaw. What Mearsheimer elides is that there is a fundamental distinction between being a hegemon and bidding for hegemony. And given that “[s]urvival is the number one goal of great powers,” the crucial, behaviorally determining question is not: If I were the hegemon, would I be more likely to survive? Rather, it must be: If I make an aggressive bid for regional hegemony, will I be more likely to survive than if I do not embark on such an adventure? And here the answer should be obvious, to any rational great power: bidding for hegemony is one of the few and rare paths to destruction. Most great powers are extremely likely to survive; most great powers that bid for hegemony do not.
Consider the contemporary case, which arguably motivates the entire theory. Is China’s “survival” really in jeopardy if it does not aggressively bid to dominate all of Asia? Will the United States not “survive” if it fails to reach across the Pacific Ocean to crush a rising China? (Puzzlingly, the US, as a regional hegemon, should have already achieved Mearsheimer’s big brass ring of preternatural security.) What exactly threatens the survival of these great powers? Given their military establishments, their nuclear deterrents, their economic might, their continental size, and their vast populations, is their survival really imperiled if they do not act as offensive realists? Or is it only imperiled if they irrationally act as offensive realists, pushing everything they have across the table in a reckless bet to win it all?
Moreover, only a power with a complete ignorance of history would be eager to embark upon a bid for hegemony if its main goal was to survive. (Structural realism, of course, forbids the relevance of history.) After all, as Mearsheimer notes, the five countries in modern history that have bid for regional hegemony—with one exceptional exception—ended up utterly destroyed, with the loss of their territorial integrity and domestic political autonomy. The one “success” story, the United States, occurred under extraordinarily rare circumstances: surrounded by weak neighbors and weaker adversaries, and separated by vast oceans from all other powerful states.
Yet Mearsheimer assumes as a law of nature (and, failing that, advocates) that powerful states will behave in such reckless and likely disastrous ways. This makes no sense and urges a fool’s errand. Consider that any state in a position to even plausibly consider a bid for regional hegemony must be a very secure state—indeed, it must already be the strongest state in the region, by a considerable margin.
Such a state is already extremely likely to survive. Were regional hegemony to be achieved, it is reasonable to concede that such states will be even more secure still. But the crucial questions remain: how much more secure would they be? And what are the risks of making a militarized bid for hegemony? Given the historical record (and the facts of this case: China lives in a very crowded neighborhood populated with numerous near-great and mid-sized powers), a militarized bid for hegemony seems much less like an “inevitability” and more like something to be avoided at all costs: a fantastically risky life-or-death long-shot gamble, taken in the pursuit of a very marginal increase in state security. In sum, China’s survival would not be threatened if it failed to act according to the tenets of offensive realism; to the contrary, acting like an offensive realist is one of the very few choices that might threaten its survival.
Moreover, contemporary China, which would prove almost unimaginably hard to conquer in any event, also holds a potent nuclear force—one less reason to think its survival depends on the military conquest of others, many of whom have nuclear deterrents of their own or the capacity to develop them quickly if threatened. This again raises the question of why the preternaturally secure United States—with its own massive, robust, and secure nuclear arsenal—must, simply to ensure its own survival, throw everything it has at crushing China.
Indeed, regarding American policy, Mearsheimer’s logic is on even shakier ground. After all, offensive realism holds that the reason states want to be regional hegemons in the first place is because that status provides them with inviolable security, even from other similarly situated powers. As Mearsheimer notes, “[r]egional hegemons certainly pack a powerful military punch, but launching amphibious assaults across oceans against territory controlled and defended by another great power would be a suicidal undertaking.” Yes, indeed. Mearsheimer elaborates, repeatedly, the secure status of the regional hegemon, and in particular the distinct and enviable security of the United States. By Mearsheimer’s own logic, US survival is simply not at stake in this would-be confrontation.
Ultimately, as a classical realist perspective emphasizes, great powers like the United States enjoy the luxury of choosing from a menu of possible policy postures and positions. The key question is not of what it must necessarily do but which choices are most likely to advance its interests—keeping in mind, always, that the posture selected will shape the international political environment in which others will in turn make their strategic choices.
¤
In considering the implications of changes to the balance of power, scholars have long appealed to Thucydides and his ancient text History of the Peloponnesian War—and for good reason. As he famously wrote in a perennially quoted passage, “[t]he growth of the power of Athens, and the alarm which this inspired in [Sparta], made war inevitable.” Thucydides, however, backs up a truckload of qualifications to this simple declaration. He was generally hostile to deterministic arguments, and his analysis of the causes, course, and consequences of that war features a bevy of explanatory variables, including the decisive influence of national character, domestic politics, and quality of leadership in explaining choices and outcomes. Nevertheless, Thucydides makes plain that he saw this shift in the balance of power as a basic cause of the initial conflict (the war lasted 27 years, in three distinct phases).
It is not surprising then that, with Destined for War, Allison attempts to apply the lessons of History of the Peloponnesian War to current tensions between China and the United States. Unfortunately, Destined for War fundamentally misreads Thucydides, is wrong on the foundational “sleepwalker” analogy it seeks to establish, and is inattentive to the real “Thucydides Trap” that might lead to a tragic war—that of great power hubris.
Destined for War gets Thucydides wrong, over and over again. Allison asserts that Thucydides did not live to see the end of the war, and that “[e]very one of the six hundred pages in the History of the Peloponnesian War offers compelling details about the twists and turns along the path of this fatal war.” In fact, Thucydides witnessed the end of the war (and his exposition of the war is only intelligible in that context), and the overwhelming majority of his great work details events that took place after the war had started—it would seem that Thucydides had much more to say than simply what caused the (initial) commencement of hostilities.
The problems of Destined for War run deeper, and vitiate the lessons that Allison might derive from Thucydides, which in fact are much more valuable and profound than a simple recitation of his structural “rise of Athenian power” argument would imply. Destined for War attempts to establish an erroneous “sleepwalker” analogy to the Peloponnesian War, which can then in turn be applied to contemporary international relations.
Allison reimagines the Peloponnesian War as a tragedy that both sides wished to avoid. He asserts that Athens and Sparta each made “repeated attempts to avoid it,” and applied “their best efforts” to the pursuit of a peaceful solution. Allison even asserts that Athens’s leading citizen, Pericles, opposed the war but that his hand was forced, as he finally “bent to popular pressure and reluctantly drew up plans for war.”
This is all simply and exactly wrong. Neither side made their best effort for peace; both approached the conflict with eyes wide open. Pericles was in fact a leading advocate for the war. Nor did he come to this position reluctantly, goaded on by an aggressive public. Explicitly rejecting compromise and proposals for a negotiated solution, Pericles rallied the more cautiously inclined Athenians with a rousing speech, urging them to share his view that the choice for war was an absolute necessary. The people did not sway Pericles—rather, despite formidable public opposition, Thucydides reports that the public voted for war because they were “persuaded of the wisdom of his advice.” Nor did the Spartans search eagerly for a peaceful solution. And they came to regret doing so, subsequently acknowledging explicitly that they had been in the wrong, for several reasons, including “their own refusal to listen to the Athenian offer of arbitration.” Athens and Sparta did not sleepwalk into an unwanted war; they willfully embraced it, fueled by Athenian arrogance and Spartan intransigence.
Worst of all, Allison misses Thucydides’s most important point. The great historian did warn of a trap, worthy of his name, and it is the principal theme of his magisterial book. But the real “Thucydides Trap” derives from a concept that is incompatible with structural realism: great power hubris. A reader of Destined for War would be forgiven for concluding that Thucydides was warning his readers about a “trap” that Athens and Sparta fell into when war first broke out between them. But Thucydides, a great admirer of war-advocate Pericles, did not situate the Athenian tragedy in that initial decision but rather in subsequent, serial Athenian follies rooted in hubristic overambition. Over the very long course of the war, Athens repeatedly and disastrously “grasped at something further” and ultimately caused its own undoing—definitively, 16 years after the initial outbreak of the war, via their ill-fated invasion of Sicily. As Hunter R. Rawlings, author of the 1981 book The Structure of Thucydides’ History, explains, “Thucydides clearly regards the Athenian adventure in Sicily as the greatest event of his war, and its conclusion as the greatest defeat in Greek history.”
That denouement, with Athens destroyed, was not due to the merciless logic of structural factors but by unchecked, intoxicating hubris. Sicily passes unnoticed in Destined for War. But the real Thucydides Trap is not found in changes to the balance of power; it is reflected in the arrogance of power that led Athens to ruin on the distant shores of the western Ionian Sea. And if the United States and China come to blows, it is likely that they will have failed to learn Thucydides’s timeless teachings about great powers grasping for more—not because they must, but because they think they can.
¤
Structural realism has driven, as the old song goes, 90 miles an hour down a dead-end street. But realism, in particular classical realism, still has much of value to offer. Firmly within the mainstream of the realist tradition (indeed, it established that tradition), classical realism parts company with its intellectual cousins in its insistence that the social world is not governed by iron laws and its understanding that, crucially, politics matters.
Rather than security as scarcity, classical realism recognizes that most great powers, most of the time, are extremely secure. They can safely choose from a fairly broad menu of policy options, and, because we do not have a single unified theory of international politics, what makes for the “best” choice can easily be contested within societies.
Great powers, then, enjoy the luxury of choice. And they spend most of their time not struggling to survive but attempting to advance their (distinct, historically contextualized) aspirations—ambitions motivated not only by fear but also by desire. China, for example, is orders of magnitude more secure than it was 40, 80, and 150 years ago; if all it cared about was its survival, it would need less foreign policy, not more. Great powers like China and the United States make choices, and those contested and politically driven choices matter. Because, like oligopolists in an economy, they are not just subject to market forces; their behavior shapes the nature of the market itself. Thus we live in a world of contingency—great power choices will have fundamental consequences for what will happen next, for better or worse.
This sounds, perhaps, hopeful. In fact, however, a classical realist perspective looks at the rise of China even more pessimistically than structural realism. Recall that Mearsheimer and Allison anticipate a regrettable tragedy—for the former, China’s militarized bid for regional hegemony is not driven by “wicked motives” but simply the desire to survive; for the latter, both sides are stumbling purposelessly into an avoidable trap.
Classical realists, on the other hand, see politics as the clash of interests, with countries harboring competing ambitions, driven by an appetite for power and primacy as ends in themselves, not simply as means to assure security. Robert Gilpin saw it as axiomatic that “[a]s the power of a state increases, it seeks to extend […] its political influence.” Emerging great powers commonly seek not just security but also status, prestige, and even deference from others—not because they feel vulnerable due to anarchy, but because they are increasingly and often voraciously ambitious. Raymond Aron warned, in his 1983 book The Committed Observer, that world politics was a “game for gangsters”—and like mob boss Johnny Rocco in John Huston’s 1948 film Key Largo, when rising powers are asked what they want, the answer is generally “more.”
Thus, classical realism roots the problem not in tragedy but in hubris and fear: it is very likely that a rising China will become increasingly arrogant and throw its weight around, and the United States, accustomed to being the superpower in a one-superpower world, will be at first too arrogant and then too anxious to take the measures necessary to wisely navigate the realities of the changes to the international balance of power.
Paradoxically, although classical realism is even more pessimistic about the implications of a rising China than narrowly structural analyses are, it is nevertheless considerably more measured in its implied policy advice than that which is commonly associated with approaches labeled “realist.” This caution is rooted in the hallmarks of classical realism: the primacy of politics, the centrality of contingency, and the tempering discipline of prudence. All this means that, while history suggests that a militarized bid by China for regional hegemony cannot be ruled out (great powers are generally rational, but occasionally reckless), the principal challenge, as realists like George F. Kennan recognized during the Cold War, is political.
To be clear, classical realism is quite gloomy and pessimistic about all this. It expects China to behave the way that emerging great powers have commonly comported themselves: boorish, antagonistic, and presumptuous. Nevertheless, from a classical realist perspective, the principal challenge remains political. The present danger is not that China will serially invade its neighbors but that it might come to politically dominate the region as local powers, seeing no alternative, increasingly defer to its wishes. This outcome would most likely be the result of revised political calculations, not military conquest.
China might be so foolish as to launch a major war—but, contra offensive realism, such an act of geopolitical self-mutilation is not inevitable; it is not even likely. The greater danger is that, indeed, the United States and China might fall victim to the real Thucydides Trap—that toxic cocktail of hubris and arrogance that leads great powers to overestimate what their military prowess might achieve. Realism demands that we see the world as it is, not as we might wish it to be, and it falls to the US to realize that China, much more powerful than it once was but a few decades ago, will want more and, in many cases, will get more. Rather than seeking provocation and confrontation, however, which will likely make a difficult situation much worse, realism demands that the Americans, rather than joining a contest for regional military supremacy (which the realities of economics and geography suggest would be an expensive and unlikely prospect), should sustain sufficient capabilities and deep engagement with regional partners to provide local actors with the confidence to resist encroachments on their political autonomy. From a classical realist perspective, to fail to do so would invite tragedy.
¤
* There are, of course, numerous learned experts on contemporary US–China relations who offer more sophisticated appreciations of this fraught and challenging bilateral relationship. See, for example, Jessica Chen Weiss, “The China Trap: U.S. Foreign Policy and the Perilous Logic of Zero-Sum Competition,” in Foreign Affairs (2022); M. Taylor Fravel and Charles L. Glaser, “How Much Risk Should the United States Run in the South China Sea?” in International Security (2022); and Thomas J. Christensen, “There Will Not Be a New Cold War,” in Foreign Affairs, (2021). Unfortunately, the hawkish bipartisan consensus within the Beltway is so singular and so harmonious that these voices are too easily drowned out. Such specialists are often casually dismissed as “idealists”—or worse.
¤
Jonathan Kirshner is a professor of political science at Boston College. He is the author of numerous books, including An Unwritten Future: Realism and Uncertainty in World Politics (2022), American Power After the Financial Crisis (2014), Hollywood’s Last Golden Age: Politics, Society, and the Seventies Film in America (2012), and the novel Urban Flight (2015).