In This Review
An Unwritten Future: Realism and Uncertainty in World Politics

An Unwritten Future: Realism and Uncertainty in World Politics

By Jonathan Kirshner

Princeton University Press, 2022, 336 pp.
The Atlantic Realists: Empire and International Political Thought Between Germany and the United States

The Atlantic Realists: Empire and International Political Thought Between Germany and the United States

By Matthew Specter

Stanford University Press, 2022, 336 pp.

It’s not a great time to be a realist. Although many prominent realist theorists of international relations correctly predicted the war in Ukraine, their focus on great-power politics over the rights of small states and their warnings about the risks of escalation have not been popular among the foreign policy commentariat. The insistence of some realists, chief among them John Mearsheimer, that the war is almost entirely the result of the structural factor of NATO’s expansion rather than the bellicosity of Russian President Vladimir Putin has not endeared realism to a broader public audience, either. According to the scholar Tom Nichols, the war in Ukraine has proved that “realism is nonsense.” 

Some of this is just realism’s normal public relations problem when it comes to ethics and human rights. One of the main philosophical traditions of international politics, realism sees power and security as being at the center of the international system. Although the school of thought comes in a variety of flavors, nearly all realists agree on a few core notions: that states are guided primarily by security and survival; that states act on the basis of national interest rather than principle; and that the international system is defined by anarchy. 

None of these notions are pleasant or popular. The realist Robert Gilpin once titled an article “No One Loves a Political Realist.” All too often, pointing out the harsh realities of international life or noting that states often act in barbaric ways is seen as an endorsement of selfish behavior rather than a simple diagnosis. As one of the school’s founding fathers, Hans Morgenthau, put it, realists may see themselves as simply refusing to “identify the moral aspirations of a particular nation with the moral laws that govern the universe.” But their critics often accuse them of having no morals at all, as the debate over Ukraine has shown.

As if on cue, two new books seek to address realism’s flaws and its promise by looking back at the history of classical realism—an earlier version of realism that arrived at its pessimism not by way of its analysis of the international system but through a more broadly gloomy take on human nature. Matthew Specter’s The Atlantic Realists explores the development of classical realism in the period after World War I, with a particular focus on the cross-pollination between German and American intellectuals and on the deeper and more malevolent historical roots of the concepts underlying this philosophy. Jonathan Kirshner’s An Unwritten Future, by contrast, seeks to rehabilitate classical realism as a frame for understanding modern geopolitics, particularly in opposition to more modern structural versions of realism. Whereas Kirshner seeks to praise classical realism, Specter has come to bury it. But both authors draw on a central truth about realism, which the political scientist William Wohlforth has put this way: “The most important point is that realism is not now and never has been a single theory.” Rather, it comprises a variety of models for thinking about the world, each characterized by pragmatism and the art of the possible, rather than grand and often doomed ideological crusades suggested by other schools of thought. 


Realists have been at the forefront in criticizing the United States’ disastrous foreign policy in recent decades, highlighting the folly of trying to remake the world in its image. As a result, public and even elite views have begun to swing in a more pragmatic and realist direction over the last decade. In failing to adequately explain and respond to the war in Ukraine, however, realists may face a potential backlash to that shift. 

Ukraine has long been a flash point for realist thought. Many realists argue that in the post–Cold War period, the United States has been too focused on an idealistic conception of European politics and too blasé about classic geopolitical concerns, such as the enduring meaning of borders and the military balance between Russia and its rivals. Policymakers who subscribed to liberal internationalism—the idea that trade, international institutions, or liberal norms can help build a world where power politics matter less—typically presented NATO’s expansion as a matter of democratic choice for smaller central and eastern European states. Realists, in contrast, argued that it would present a legitimate security concern for Moscow; no matter how benevolent NATO might seem from the West’s perspective, they would argue, no state would be happy with an opposing military alliance moving even closer to its borders. 

These disputes became more rancorous after Russia’s 2008 war in Georgia and its 2014 annexation of Crimea, with liberal internationalists arguing that these wars revealed Putin to be an imperialist, revisionist leader seeking to reconquer the Soviet empire. Many realists, however, maintained that these conflicts were Moscow’s attempts to prevent its closest neighbors from joining NATO. Both arguments are plausible; the Kremlin’s reasoning is hard to discern. Yet as diagnoses, they point to very different policy conclusions: if Putin is acting out of ambition, then the West should bolster deterrence and take a hard line against Russia, but if he is acting out of fear, it should compromise and accept limits on future expansion. 

Ukraine has long been a flash point for realist thought.

Since the February 24 invasion, there has been a new dimension to this criticism. The more thoughtful critiques of realism in the months after the war began noted that many realist analyses of the conflict are relatively unhelpful because they focus almost entirely on relations between the United States and Russia and ignore the internal and ideational factors that explain Putin’s decision to invade and his conduct during the conflict. Realists are probably correct that NATO’s expansion into the post-Soviet space contributed to the war, but that is at best a partial explanation. Other factors appear to have also loomed large in Russia’s prewar decision-making: the prospect of NATO armaments or bases in Ukraine (with or without its formal membership), Western training for the Ukrainian military, Kyiv’s corruption crackdown on oligarchs close to Putin, and Ukraine’s increasing economic ties to the EU. 

The war in Ukraine thus suggests that some realist theories are simply not as helpful as they could be during a time of global geopolitical upheaval; realists have the broad contours of the war in Ukraine right but get many of the details wrong. This is particularly unfortunate, as other approaches to the world—most notably the variants of liberal internationalism that dominated so much of the post–Cold War period—have also been found wanting. Proponents of primacy or liberal hegemony, for example, who argued that the United States could maintain its outsize military edge and prevent the rise of other powers, have been proved wrong by the rise of China. Liberal internationalists who endorsed wars of regime change in Afghanistan and Iraq or humanitarian interventions in Libya have seen their grand projects falter and fail. The realist theories presented in Specter’s and Kirshner’s books may not offer insights that are new, precisely, but they revise and update our understanding of a classical realist model whose pragmatism is in many ways a better fit for our newly multipolar world. 


What today is called “realism”—the school of thought most undergraduates are taught in their International Relations 101 class—is in fact structural realism or neorealism, a version of realism outlined in the 1970s by the scholar Kenneth Waltz. Neorealism is further divided into “defensive” and “offensive” variants, depending on whether one believes that states primarily seek security through defensive means, such as military fortifications and technology, or through an expansion that acquires power and territory. Both versions focus heavily on structural factors (the ways that states interact at the global level) and effectively ignore domestic politics, the quirks of bureaucratic decision-making, the psychology of leaders, global norms, and international institutions. Neorealism thus stands in stark contrast to the older school of classical realism, which counts Thucydides, Machiavelli, and Bismarck among its earliest practitioners, has strong roots in philosophy, and includes factors such as domestic politics and the role of human nature, prestige, and honor. It also contrasts with classical realism’s more modern counterpart, “neoclassical realism” (a term coined by Gideon Rose, a former editor of this magazine), which seeks to marry the two variants by reincorporating domestic and ideational factors into structural theories. 

Specter’s and Kirshner’s books both concern themselves with classical realism, in particular its role as the fount of all later realist theories. As if in a comic book, Specter seeks to unearth realism’s origin story, with a focus on the intellectual underpinnings and biographies of key players such as Morgenthau and the German theorist Wilhelm Grewe. In doing so, his intent is to prove that the genesis of realism is a much darker tale than previously understood. In the commonly told story of classical realism, German-American émigrés such as Morgenthau reacted to the bloody wars of the early twentieth century by rejecting the unfounded idealism of U.S. President Woodrow Wilson and returning to the classic notions of realpolitik espoused by such thinkers as Machiavelli and Thucydides. This narrative, as presented most famously by the British historian Edward Hallett Carr, attributes the rise of the Nazis and the outbreak of World War II to the failure of Wilson’s idealistic efforts to create a League of Nations that would resolve conflict through laws and norms instead of through realpolitik and force. 

But classical realism, Specter argues, is not actually a descendant of Bismarckian Realpolitik. Rather, it is an offshoot of the pursuit of Weltpolitik, the imperialist school of thought put into practice by the bumbling imperialist Wilhelm II in the late nineteenth and early twentieth centuries. Where the former emphasized skillful balancing between adversaries to avoid unnecessary conflict, the latter was driven more by social Darwinist notions that great powers have the right to expand and dominate. To make his case for realism’s nefarious roots, Specter looks at the origins of central concepts of classical realism, exploring terms such as “the national interest” and “geopolitics.” What he finds is that some of these terms did in fact originate decades before the mid-twentieth century, in debates about imperialism and the claims of politicians such as Wilson that rising powers like the United States and Germany were exceptional. 

Polish soldiers during a NATO exercise in Orzysz, Poland, July 2022
Polish soldiers during a NATO exercise in Orzysz, Poland, July 2022
Omar Marques / Getty Images

Likewise, Specter makes a solid case that the classical realists in many ways invented a noble lineage for themselves, identifying great historical philosophers whose work fit in with their notions of the world (such as Hobbes) while eliding or avoiding altogether their more questionable historical antecedents. He spends significant time exploring the linkages between the German philosopher Carl Schmitt’s notions of Grossraum—more infamous in its later incarnation as Lebensraum, the doctrine that Hitler’s Nazi government used to justify its conquests in eastern Europe—and the later realist thinkers’ focus on geopolitics. 

This intellectual genealogy of realism is an impressive contribution. But the lessons that Specter draws from it are less convincing. Although he is correct that the classical realists of the 1950s took concepts and ideas from earlier, less ethical theories of international relations, it is not clear why such borrowing undermines their later arguments. Specter proposes that, because of these nefarious ties, realism should be viewed not as “a storehouse of accumulated historical ‘wisdom,’ but rather a historical artifact—and one that has, tragically, exerted too much power over world politics.” Yet all philosophers and scholars reach to the past for inspiration and support. So what if the classical realists looked backward for similar perspectives to bolster their case? They sought a longer, more diverse lineage for their ideas than the troubled history of the early twentieth century. It is hard to blame them for that. 

Indeed, much of Specter’s overall argument amounts to guilt by association. It is undoubtedly true that the classical realists couched their arguments in terms that would have been familiar to early-twentieth-century imperialists. But they added to that legacy, as Specter himself notes, “ethical seriousness” and “caution.” These elements were as much a reaction against the ideas and events they had witnessed over the preceding decades as anything else. That there are darker variants of realism in history should not tarnish its more modern incarnations. Indeed, the same could be said for today’s foreign policy debate. There are undoubtedly realist approaches to the world that espouse power-seeking and U.S. military primacy. But there are also more ethical and defensive variants that take the core insights of realism but do not accept the amorality or imperialist principles of realism’s earliest roots. Some realists are heartless hawks who would sell their own mothers; others are thoughtful doves who regret the necessity of difficult choices. For every Henry Kissinger, there is a George Kennan. 


Kirshner’s targets in An Unwritten Future are closer to the present day. Kirshner savages the theories of structural realists, which he argues are excessive in their devotion to rationalist causes of war and cannot explain anything other than stasis in the international system. In stripping down realism to a more parsimonious model, one in which the only truly important variable is power, Kirshner argues, the structural realists have gone too far, producing a theory of little value. In proposing what he sees as a more useful way to assess the world, he draws on a wave of recent scholarship by academics who are agnostic about paradigms such as realism and liberalism. Instead, these scholars study the role of honor and prestige in international affairs, factors that were central to classical realism. Kirshner argues that contemporary thinkers should resurrect the classical realist models of the world, bringing in domestic political and ideational factors, and avoiding what he sees as the pitfalls of neorealism’s “hyper-rationalist” view of the world.

In Kirshner’s view, clashes between states may sometimes arise from misperceptions or from the security dilemma, in which one state’s attempts to make itself secure unintentionally make a neighboring state less secure. But in addition to these causes, which structural realists would accept as relevant, he believes that war may as often arise from differing worldviews or different hierarchies of interests in different states, factors that structuralist realists tend to ignore. Kirshner also correctly identifies many of the core problems that structural realists have faced in recent years: how to reconcile morality with a fundamentally amoral theory, the malleability of the notion of the national interest, and the limits of realism as a guide to purposeful action rather than as a guide to what not to do. 

Kirshner argues bluntly that structural realism is often better at pointing out the errors in others’ approaches than at suggesting its own solutions, a criticism that will ring true to anyone who has followed the debates over the causes of the Ukraine invasion. Indeed, An Unwritten Future is at its strongest when arguing that war is a plunge into radical uncertainty. (It is weakest when playing inside baseball, pointing out internal contradictions in the ways structural realists have borrowed their models from economics.) Structural neorealism cannot fully explain why and when wars happen or how leaders and populations will react when they do. Six months ago, who would have believed that an actor whose primary claim to fame had been playing a president on television would have pulled Ukrainians together in defiance of an invasion, spurring the creation of a new and unified national identity? War, as Kirshner underscores, can be understood only by incorporating human factors into the analysis. 

Kirshner’s problem with later generations of realists stems from their response to the challenge from liberalism. Liberals believe that states can rise above conflict and power politics, although they differ on whether that can be achieved through trade, international institutions, or international law; realists simply do not believe transcendence is possible. In the face of this disagreement, rather than accepting that the two schools were based on entirely different ideological assumptions, neorealists adopted social scientific language and framing, in the hopes of making their own beliefs seem scientific, rather than ideological, in nature. In fact, Kirshner says, both realism and liberalism have ideological bases, and contemporary realists should stop pretending to be scientists and return to the messier but more analytically rich terrain of classical realism.


The debates over Ukraine, and over U.S. foreign policy more broadly, are in many ways simply rehashing long-running criticisms of realist or restraint-minded thinkers. As Kirshner highlights, because most realists emphasize prudence above all else, it is much easier for them to criticize than it is to offer a different, affirmative policy as a replacement. As a result, there is no one realist policy. For example, realists were clear and united in their criticisms of the war on terrorism—they nearly unanimously opposed the invasion of Iraq—but far less so on the question of what they believe should replace it. Some call for a new crusade against China, and others for a U.S. drawdown in many regions. This division makes it hard for realists to shape the policy process in this or future administrations. 

Yet even if realism is largely present in today’s policy debates as a foil, pushing U.S. foreign policymakers to justify their choices and perhaps adopt slightly more pragmatic options, that may be the best that realists can hope for. As Specter points out, realists have had a complicated relationship with policymaking. Kennan, who served as the U.S. State Department’s director of policy planning, and Morgenthau, who worked under him, are among the best-known realist policymakers, and their influence has waxed and waned over time. The most realist administrations—those of Presidents Richard Nixon and George H. W. Bush—had some notable policy triumphs: ending the Vietnam War, managing the peaceful breakup of the Soviet Union, winning the Gulf War. But they also had mixed legacies, from Nixon’s troubled domestic political record to Bush’s 1992 electoral loss. That is still more than one can say for realist influence in the Clinton, George W. Bush, and Obama administrations, when unchallenged U.S. power allowed idealists to drive most policy. Yet as the world continues its shift toward multipolarity, realist insights will once again become more important for the conduct of U.S. foreign policy. 

This makes Specter’s and Kirshner’s books particularly valuable. That both consider realism’s antecedents and insights without using some variant of liberalism as a straw man is equally impressive. “Paradigms are inescapable,” Kirshner writes. “Paradigm wars are largely vacuous.” Neither book wastes time in irresolvable philosophical disputes. Yet it is also ironic that both books are in some ways guilty of the very charge they level at realist theories: Specter and Kirshner provide excellent critical overviews of the problems with these theories but fall short in providing alternatives. 

On this front, Kirshner’s book performs notably better. With chapters on the rise of China, how to meld political economy questions into classical realist theories, and even exploring the potential weaknesses and shortfalls of classical realism, An Unwritten Future thoughtfully assesses the question of what it would mean in practice to reinsert classical realist perspectives into ongoing policy debates. Classical realism suggests that the United States should be extremely wary of China’s rise and that Chinese ambition will rise with Chinese power. It also suggests that Washington should seriously consider ways to come to terms with and accommodate this rise, within limits, lest it accidentally provoke an earth-shattering great-power war like those in 1815, 1914, or 1939. 

Realists have had a complicated relationship with policymaking.

Despite these insights, Kirshner’s conclusions are not earth shattering. Although arguing that “after three-quarters of a century, it is more than appropriate for any great power to reassess the nature of its global commitments,” he ends by advocating that the United States maintain the status quo in foreign policy, contending that a leap into the unknown—in effect, any major changes—does not comport with realism’s emphasis on prudence. This is a frustrating conclusion, as it suggests a level of stasis in the international system that the book itself belies when discussing the rise of China. 

Specter, on the other hand, largely punts on the question of the future of U.S. foreign policy. In arguing that realism is too deferential to imperial approaches, too undemocratic, and too rooted in ethically questionable philosophy, he makes clear that he doesn’t regard realism as a reasonable path forward, at least not until it incorporates postcolonial, feminist, and critical theoretical insights. This distaste mirrors much of the progressive unease with pragmatism and moderation in foreign policy when those notions come into conflict with universal values. At times, this tension has produced uncomfortable internal debates among progressives over humanitarian intervention—for example, in Syria—pitting those who argue that the United States has a responsibility to protect human rights around the world with those who argue that such interventions would do little but drag the country further into endless Middle Eastern wars. 

But the realists have never been blind to this tension. As Morgenthau himself wrote in his classic treatise Politics Among Nations, “Political realism does not require, nor does it condone, indifference to political ideals and moral principles, but it requires indeed a sharp distinction between the desirable and the possible.” Realists accept that foreign policy is often a choice between the lesser of evils. Pretending otherwise—pretending that moral principles or values can override all constraints of power and interest—is not political realism. It is political fantasy.

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