A World of Power and Fear

What Critics of Realism Get Wrong
Ukrainian soldiers in the Zaporizhzhia region of Ukraine, April 2022. (Ueslei Marcelino / Reuters)

Among the collateral damage of the war in Ukraine is a school of thought: realism. This intellectual tradition insists that the pursuit of national interests trumps higher ideals, such as the commitment to open trade, the sanctity of international law, and the virtues of democracy. Realists focus on how states, particularly major powers, seek to survive and retain influence in world politics. As such, realism appeared well suited for explaining the imperatives and calculations behind the Russian invasion. Instead, it found itself caught in the crossfire. After realist arguments seemed to excuse the Kremlin’s actions, critics in Europe and North America have variously called prominent individuals associated with realism—and realism itself as a doctrine—irrelevant, callous, and even morally reprehensible.

The political scientist John Mearsheimer drew much of the opprobrium for his claims about the origins of the war in Ukraine. An unabashed advocate of realism, Mearsheimer has insisted that the United States and its allies are at fault for encouraging NATO and EU expansion into what the Kremlin sees as its sphere of influence, thereby threatening Russia and provoking Russian aggression. Criticism of Mearsheimer mounted after the Russian Foreign Ministry itself promoted his ideas in the wake of the invasion. The urgings of another realist, former U.S. Secretary of State Henry Kissinger, exhorting Ukraine to give up territory in order to appease Putin have also led to a barrage of attacks on the tenets of realism.

But realism’s critics should not throw out the baby with the bath water. The invective directed at realism misses an important distinction: realism is both an analytical school of thought and a policy position. The errors of the latter don’t obviate the utility of the former. In explaining the war in Ukraine, realism, like any theoretical framework, is neither good nor bad. But even when its prescriptions can seem unsound, it retains value as a prism through which analysts can understand the motivations and actions of states in an inevitably complex world.


From the 1960s to the 1990s, the field of international relations was riven by the so-called paradigm wars. Scholars feuded over the best way to think about—and how to study—international politics. These debates were nuanced, but they essentially boiled down to a clash between those who held a realist view of international politics and those who did not.

Realism comes in many hues. Some realist approaches emphasize the importance of individual leaders, others stress the role of domestic institutions, and still others focus squarely on the distribution of power among countries. There is classical realism (human nature compels states to pursue security), structural realism (the lack of a world government compels states to pursue security), and neoclassical realism (a combination of internal and external factors compels states to pursue security). These approaches have their own subvariants. For instance, structural realists are divided between a defensive camp (states seek security by preventing the hegemony of any single power) and an offensive camp (states must seek hegemony to achieve security). Some realists would disavow the label altogether: the work of the British historian E. H. Carr is clearly realist in its leanings, but he would never have identified himself as such.

Rather than being a strictly coherent theory, realism has always been defined not by what it prescribes but by what it deems impossible. It is the school of no hope, the curmudgeon of international relations thought. The first work of modern realist thought and the precursor to Mearsheimer’s own work was The European Anarchy, a short book written by the British political scientist G. Lowes Dickinson in 1916. It emphasized that states, out of fear, will seek to dominate and, indeed, gain supremacy over others. During the 1920s and 1930s, realists (although not yet referred to as such) pointed to the futility of arms control and disarmament treaties.

In 1942, the American scholar Merze Tate published The Disarmament Illusion, a book that argued that states will inevitably seek to retain their arms and whose ideas fit well with the claims made by the later realists Hans Morgenthau and Kenneth Waltz. In the late 1940s and 1950s, Kissinger and Morgenthau pointed to the impracticality of hoping for a single world government or even peaceful coexistence among countries. In the 1970s and 1980s, realists were primarily identified (either by others or by themselves) as those who derided the hope that international regimes, such as the United Nations, could solve global problems. By the 1990s, realists were criticizing the expectation that international institutions and the spread of democracy would usher in a golden age of global peace and prosperity troubled only by the occasional rogue state.

Realism fared quite well compared with an alternative theory that gained prominence in the 1990s and continues to receive attention in policy circles: the notion that geopolitics would become a “clash of civilizations,” as advanced by the American political scientist Samuel Huntington. Like Mearsheimer’s core realist work, Huntington’s thesis was written in the wake of the Cold War, as analysts and scholars sought to anticipate what the end of superpower bipolarity would mean for the world. While Mearsheimer focused on the return of great-power politics, Huntington claimed that it would be cultural, largely religious, differences that would drive the conflicts of the future. Huntington was, in effect, rebutting the work of Mearsheimer. In contrast to the statist emphasis of realism, Huntington’s culture-based theory predicted peaceful relations between Ukraine and Russia, countries that in his view belonged to the same overarching civilization. That prediction has not aged well.

What ultimately unifies the branches of realism is the view that states bristling with arms are an inescapable fact of life and that international cooperation is not just difficult but fundamentally futile. In essence, it is foolish to hope that cooperation will provide lasting solutions to the intractable reality of conflict and competition as countries pursue their own interests.

That is the framework that characterizes realist thought, including the work of Mearsheimer. Realism sees international politics as a tragic stage in which the persistence, if not the prevalence, of war means that governments must focus on guaranteeing national security, even at the expense of liberties and prosperity. Tate captured this sentiment well in The Disarmament Illusion: “Dissatisfied powers may not actually want war, may even dread it, and may be quite as unwilling to run the risk of an appeal to arms as the satisfied states; but in spite of this, they will not voluntarily shut off all possibility of obtaining a state of things which will be to them more acceptable than the present.”


Realism as a theory gains power by highlighting the mechanisms that constrain human agency, be they the innate nature of humans (as emphasized by Morgenthau) or the distribution of global power (the focus of Waltz). To draw an analogy, realism’s role is to continually point to the gravity that undercuts human attempts to fly. Realism can be used to explain the foreign policy choices of certain countries or why an event, such as a war, occurred. As a theory, realism can be very effective in explaining relations among states. But it becomes something different when it journeys from the realm of description to that of prescription. When brought into policy, realist theory becomes realpolitik: the position that states should balance against their adversaries and seek relative gains rather than accept supranational and institutional constraints on their freedom of action in international affairs.

The distinction between realism as theory and as policy appears in the historical debate over nuclear proliferation. In the early 1980s, Waltz argued that the spread of nuclear weapons would lead to greater peace. He cut against the conventional wisdom that insisted that only limiting the spread of these weapons would ensure a safer world (the logic behind the creation of the Nuclear Nonproliferation Treaty in 1970). His claim was subsequently debated by those who, to put it simply, pointed out that the proliferation of nuclear weapons would make the world more dangerous.

In making his arguments, Waltz took a descriptive and theoretically informed observation (the likelihood of war decreases as deterrent and defensive capabilities increase), applied this to nuclear weapons (nuclear weapons dramatically improve a country’s deterrent and defensive capabilities), and then deduced a recommendation for how policymakers should view the spread of nuclear weapons: that more should be welcomed, not feared.

It is in this last step that Waltz goes from describing international politics (here is why states seek nuclear weapons) to prescribing international politics (here is why states should seek nuclear weapons). One is a description, the other is a justification. They are both valid intellectual enterprises, but they should not be confused. A particular understanding of world events does not inevitably lead to a particular policy response. In this case, the same factors that led Waltz to justify the spread of nuclear weapons could have led him to offer the opposite prescription, in that a state’s security goals could be achieved without them (for instance, by sheltering under the nuclear umbrella of a major power). Realist theory helps describe the world, but such prescriptions reflect the interpretations of individuals, not the overarching theory itself.

Realism as policy also manifests itself in debates over restraint in U.S. foreign policy. Proponents of U.S. restraint aim to counter liberal internationalism, the view that the United States must be involved, militarily if necessary, in foreign arenas for the sake of promoting and maintaining a rules-based international order. By contrast, restraint calls for the United States to reduce its global footprint and avoid getting involved in issues that are marginal to U.S. national interests. As with the debate over nuclear proliferation, realism’s role in debates on how the United States should behave in international affairs must not be confused with using realism to describe U.S. foreign policy. Realism can explain why the United States finds itself in a particular geopolitical situation, but it doesn’t offer an obvious answer about how the United States should behave in that situation.


The debate regarding Ukraine has long featured realist voices. In 1993, Mearsheimer wrote in Foreign Affairs that Kyiv should retain the stockpile of nuclear weapons it inherited after the collapse of the Soviet Union because Moscow might one day seek to reconquer Ukraine. Some 20 years later, Mearsheimer wrote of how NATO enlargement and the promise of bringing Ukraine into the alliance provoked Russian aggression, namely the seizing of the Crimean Peninsula in 2014. Both pieces were focused on policy prescription: rather than simply describing what Russia, Ukraine, the United States, the European Union, and NATO were doing, they focused on what they should do. 

Although one can disagree with those arguments, it is worth pointing out that they reflect realism as policy, not realism as theory. Realism as theory would have limited itself to explaining why the crisis is happening, perhaps focusing on how the desire of major powers to dominate their region means that Russia would eventually seek to militarily coerce (or even invade) its neighbors, or that conditions were conducive to a former empire seeking to reestablish itself, or that in their search for security, states can act in ways that can be perceived incorrectly as being aggressive. 

None of this is to say that realism or any one theory offers the best explanation for the war in Ukraine. Alternative explanations abound, including the power of nationalism, the differences in regime types, and the traits (one might say, quirks) of particular leaders. But realism offers a useful frame for understanding this war’s onset. Indeed, the enduring power of realism is its ability to offer a clear baseline for coming to grips with why the world is and will likely remain a world full of pain and despair.


This article was originally published by Foreign Affairs. 

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