Requiem for a Realist

The legacy of Kenneth Waltz.

By , an assistant editor at Foreign Policy from 2013-2014.

Earlier this week, Kenneth Waltz, one of the world's most influential scholars of international relations, died at the age of 88. His books Man, the State, and War  and Theory of International Politics are classics in the field, and his influence on students, colleagues, and policymakers was profound. Waltz was a theorist who also delved into the most contentious debates in U.S. foreign policy, opposing the wars in Vietnam and Iraq and earning himself a reputation as a realist far outside the confines of the ivory tower. As Stephen Walt noted here last week, "Ken showed that you could be a theorist and a social scientist without joining the 'cult of irrelevance' that afflicts so much of academia." To take a closer look at Professor Waltz's career, FP has assembled this collection of short essays on his contributions to political science and beyond.

Earlier this week, Kenneth Waltz, one of the world’s most influential scholars of international relations, died at the age of 88. His books Man, the State, and War  and Theory of International Politics are classics in the field, and his influence on students, colleagues, and policymakers was profound. Waltz was a theorist who also delved into the most contentious debates in U.S. foreign policy, opposing the wars in Vietnam and Iraq and earning himself a reputation as a realist far outside the confines of the ivory tower. As Stephen Walt noted here last week, "Ken showed that you could be a theorist and a social scientist without joining the ‘cult of irrelevance’ that afflicts so much of academia." To take a closer look at Professor Waltz’s career, FP has assembled this collection of short essays on his contributions to political science and beyond.

Robert Gallucci: Remembering the professor

Richard K. Betts: Ever the realist

Scott D. Sagan: Remembering the nuclear strategist

Ken Booth: The Darwin of international relations

Yan Xuetong: Teaching Waltz in Beijing

Barry R. Posen: How Waltz changed international relations

Remembering the professor

By Robert Gallucci

Forty-six years ago, I was a first-year grad student at Brandeis University when I went to see Ken Waltz to find out what I needed to know to be his teaching assistant for an undergraduate course in international relations. "It’ll be easy," I remember him saying, "because you’ll be taking my graduate seminar in IR theory at the same time."

It wasn’t easy. His lectures to undergrads covered political theorists who addressed the international system of nation-states and how it explained the conditions of war and peace in a whole range of historical periods — from the Greek and Italian city-states, through Bismarck’s Europe, to the Cold War world of the 1960s. The graduate seminar was different: Not fewer than five books were required reading for each anxiety-filled class, and there was an optional reading list that actually induced depression. Waltz lectured the undergrads and led the graduate seminar. He did both brilliantly — better than I had ever seen. He had great praise for those writers and thinkers he thought intelligent, and withering criticism for those he judged soft-headed or lacking the analytical capacity essential to theory.

Ken was my thesis advisor until he left Brandeis for Berkeley. His own thesis had arguably become the most important book ever written on international relations theory: Man, the State, and War. His parting words to me as he sent me off to write mine were, "Bob, please don’t try to write MSW, just write something serious." It was extraordinarily good advice. He was also sympathetic to my desire not to serve in Vietnam, to a point. I recall him noting that since he had been unlucky enough to have caught the end of World War II and the beginning of the Korean War, I might understand if his sympathy for my vulnerability to the draft was limited.

Ken’s scholarship went against conventional wisdom. He argued that the U.S.-Soviet competition that defined the bipolar structure of the postwar world was not to be deplored for its zero-sum character, but embraced for its stability. He argued that democracy does not handicap governments in the competition among nations as most observers did but actually improves a country’s foreign policy. Most controversially, he argued that, when it comes to the number of states that have nuclear weapons, "more may be better."

We differed on the last point, and sometimes on the key, recurring question of American foreign policy: When is military intervention justified, by which he meant, when is it in the national interest? Waltz had no patience for "liberal intervention," or what we might now call humanitarian intervention, because we could never be sure that we would succeed in making things better over the long-term. And he had little patience for supposed national security arguments that could not identify a threat to vital interests — we are not, and therefore should not act like, an empire. Waltz was not an isolationist, but he was definitely a minimalist when it came to the use of force.

Kenneth Waltz’s writing has influenced the way generations of students think about international affairs. That will continue for as long as nations live in "a state of nature." But now, those of us fortunate enough to have been his students and enjoyed his mentorship have lost a most valued friend and colleague.

Robert Gallucci is president of the John D. and Catherine T. MacArthur Foundation.

Ever the realist

By Richard K. Betts

Like any truly great thinker, Ken Waltz defied stereotypes. The preeminent hard-headed theorist of power politics, he savaged the hopes of those who believe that moral energy, liberal principles, or democratic crusades can end war. But he belied the common assumption that realists are callous hawks who relish the use of force. He opposed the Vietnam War, the Reagan military buildup, and the 2003 invasion of Iraq as overreactions to threats that were exaggerated and could be handled by calm containment and deterrence.

Ken saw world politics as an anarchic "self-help system" because no enforcement authority exists above the level of nation-states. But he also believed that sensible leaders can nevertheless preserve peace if they give up ambitions to control the world and instead craft balances of power that make the costs of war clearly exceed the gains. This simple idea was in the grand realist tradition, but Waltz developed it with much greater analytic precision and clarity. And as a theorist he took it to logical conclusions that were not always persuasive in the frequently illogical world of policy. This was evident in his argument that nuclear proliferation is benign because the prospect of mutual annihilation makes the risk of war unthinkable to rivals in unstable regions, as it did for the superpowers in the Cold War.

Like other great thinkers, Waltz was sometimes the victim of false charges about what he claimed. Many who fail to read his work carefully accuse him of denying the impact of domestic politics on foreign policy. His second book, Foreign Policy and Democratic Politics, was actually all about that. A basic point of his work in general that many miss is that a theory of foreign policy is not the same as a theory of international politics. Psychological and domestic political impulses account for what nations try to do at any particular time (foreign policy). The constraining structure of the international system, however, subjects those intentions to opposing forces and thus accounts for typical results over time. States sometimes do choose poli
cies based on ideology, culture, or leaders’ idiosyncrasies that do not take sober account of their adversaries’ power, but when they do, in Waltz’s words, they "fall by the wayside." Wars happen because there is no higher authority to prevent foolish risks.

On a few points Ken had a bit too much confidence in the conclusions to be drawn from theoretical logic, as in his certainty about the future stability of mutual nuclear deterrence. When the immediate prospect of apocalypse is not at issue, however, he fully realized that policymakers all too often fail to recognize the logic of restraint. He once told me he bought stocks in the defense industry as the Cold War reheated in the late 1970s not because sharply increased military spending would be the right choice for American policy, but because he knew it would happen. Ken Waltz, ever the realist.

Richard K. Betts is the director of the Saltzman Institute of War and Peace Studies at Columbia University.

Remembering the nuclear strategist

By Scott D. Sagan

Kenneth Waltz was one of world’s preeminent theorists of international relations. He was also a hugely influential nuclear strategist, especially concerning the consequences of the spread of nuclear weapons. The first observation is widely recognized; the second observation is not. Waltz, like other realists such as Hobbes and Machiavelli, was reluctantly respected for his insights about how the anarchic nature of international politics creates self-help imperatives and pressures all states to be "nasty and brutish" so that their lives will not be "short." But American security specialists have often viewed Waltz’s views about the positive, "stabilizing" effects of nuclear proliferation to be radically outside the mainstream and thus not influential.

But this is a narrow, inside-the-Beltway perspective, for Waltz’s writings on nuclear proliferation were widely read around the globe and provided an alternative perspective that helps explain why U.S. fears about nuclear proliferation are not always shared by other governments. His seminal work on this subject — a 1981 Adelphi Paper provocatively entitled "The Spread of Nuclear Weapons: More May be Better" — presented a simple but controversial argument: Nuclear weapons are so destructive that the threat of retaliation with even a small arsenal will easily deter any state that faces a nuclear adversary. If this is true, then new countries that get nuclear weapons will behave like the superpowers during the Cold War, issuing threats and huffing and puffing in crises but avoiding war.

This view was not popular in Washington, but it was popular elsewhere. I speak from experience, for I have been a long-standing critic of Waltz’s perspective on nuclear proliferation. He and I published three editions of a popular "debate book" about the spread of nuclear weapons, and we engaged in spirited public debates about the subject in venues ranging from bookstores in Berkeley to lecture halls at Columbia, from State Department seminars in Washington to War College courses in New Delhi. And while my "proliferation pessimist" position — based on theories about common organizational failures and pathologies in civil-military relations — usually "won over" audiences inside the District of Columbia, when we traveled overseas together, he usually had the audience in the palm of his hand. They commonly cheered when he accused American officials of being ethnocentric or even racist for believing that the United States can safely enjoy the benefits of nuclear deterrence, but that other countries cannot.

Government officials and military strategists in states that are developing nuclear weapons or thinking about doing so often have echoed Waltz’s claim that "nuclear weapons make wars hard to start." And if a scholar’s influence can also be measured by the importance of the critics he or she attracts, it should be noted that Israeli Prime Minister Benjamin Netanyahu publicly disagreed with Waltz’s 2012 Foreign Affairs article, "Why Iran Should Get the Bomb," on Meet the Press.

Waltz made friends and foes alike think more clearly and argue with more rigor. That is no small legacy. He will be missed.

Scott D. Sagan is the Caroline S.G. Munro Professor of political science and senior fellow at the Center for International Security and Cooperation at Stanford University. His most recent book, co-authored with Kenneth N. Waltz, is The Spread of Nuclear Weapons: An Enduring Debate (2012).

The Darwin of international relations

By Ken Booth

It is difficult to imagine the academic study of international relations today in the absence of the work of Ken Waltz. There can be little doubt, even on the part of his critics, that he has been the single most significant figure in our field in the postwar era.

Waltz is to the study of international relations what Darwin is to the study of biology. I make this claim in terms of the sheer intellectual significance of his theoretical contribution. One cannot make sense of the biological world apart from Darwin’s theory of evolution: equally, Waltz’s structural framework for understanding how states interact under anarchy, with an uneven distribution of power and a desire to survive, offers a powerful theory for making sense of the international system. Neither theory explains everything in their domain — one always needs to know more about particularities — but both provide compelling big-picture explanations of their domains.

Waltz wrote few books over a long career. He liked to say that "we don’t need more books, we need better ones," and he practiced what he preached. Man, the State, and War (1959) and Theory of International Politics (1979) are both classics, with time-transcending significance and influence. The levels-of-analysis approach to the causes of war in the earlier book was a decisive contribution to grappling with the discipline’s traditional core problematic, while the "parsimonious" theory in the later book had a profound impact throughout the discipline.

Nobody has influenced the field as deeply or in as many directions as Ken Waltz. Disciples and critics alike are his offspring, whether their work has been to refine and develop his ideas (new schools of realism and liberalism) or to try to think outside the Waltzian world (some constructivism and critical theory). By persuasion and provocation, he lifted the discipline to a new level.

Waltz was a stubborn defender of his theory, of course, but he did not over-claim. He was not a structural determinist, nor did he think his theory necessarily timeless. In particular, he emphasized that his was a "systemic theory" of international politics, not a "reductionist theory" of foreign policy. In other words, Waltz’s theory of the international system did not tell us how the individual units in their foreign and defense policies would behave — though he had his own clear ideas about the sorts of behavior the system would reward or punish. His views about the positive utility of the controlled spread of nuclear weapons, for example, were particularly controversial.

The debates generated by Waltz’s work have made the IR discipline what it is today. His work, like that of other "realists" once thought past their sell-by dates, has been and is being re-thought. We still have much to learn from him, and in that regard Ken Waltz’s influence will live on not simply through his writings but through his impact on individual lives — as a remarkable teacher, a human being who attracted loyalty, a generous friend, an intellectual giant, and a professional role model for all who knew him. He was and will remain our indispensable theorist.

Ken Booth FBA is editor of International Relations, formerly chair of the British Intern
ational Studies Association, and E.H. Carr Professor in the Department of International Politics at Aberystwyth University.

Teaching Waltz in Beijing

By Yan Xuetong

Before I enrolled in the Ph.D. program in political science at the University of California, Berkeley in 1987, I had never learned anything about international relations theory. I took Kenneth Waltz’s Poli Sci 223 in my very first semester not because I had already heard of him but because my advisor told me that taking his course was essential. In this way, Ken became the first professor to teach me IR theory.

Due to my poor English and lack of prior knowledge, I failed his midterm exam. Ken called me to his office and told me that he understood my situation and would not count the midterm grade if I got a better grade on the final. He then spent a half-hour tutoring me on the concept of power and the idea of "system structure." Among other things, he told me that he disliked the label "neorealism" because he felt that the term told you nothing about the theory itself. Instead, he preferred "structural realism" because it described the substance of his theory.

Not only did this talk clarify my understanding of his theory, it also turned me into a student of structural theory. Since then, my own work has sought to explain how different configurations of power drive major international changes, a topic I explore at length in a forthcoming book.

Ken’s definition of theory also had a strong effect on me. He taught his students that a theory is an explanation of a law. This notion is especially important for Chinese students, who tend to use the term "theory" to refer to all kinds of political concepts. Ken’s strict definition of theory helps us to distinguish between theory and political principles, policy decisions, leaders’ ideas, religious beliefs, ideology, norms, etc. Ken’s students do not necessarily share the same view of international politics, but their works aspire to a similar level of logic and rigor.

Waltz’s work has had an enormous impact in China, where structural approaches to international politics are an increasingly important school of thought. For this reason, the Chinese Community of Political Science and International Studies has decided to hold a special panel commemorating his academic contributions at its annual conference on July 6 and 7. I am sure that it will be crowded with Ken’s disciples and that his work will continue to inspire Chinese scholars.

Yan Xuetong is dean of Tsinghua University’s Institute of Modern International Relations.

How Waltz changed international relations

By Barry R. Posen

Kenneth Waltz made critical contributions to the development of international relations theory, the debate on U.S. foreign and security policy, and the training of a new generation of international relations scholars. In the course of these contributions he has also served as a model of clarity of expression and logical argument.

Waltz’s first critical contribution to international relations theory was his elucidation of the "levels of analysis" problem in Man, the State, and War. The categorization of explanatory theories into ones that respectively stress the role of human nature; state-level political, economic, and social systems; or the anarchical condition of international politics has proven a critical building block of modern international relations theory.

Through his exploration of theories at different levels of analysis, Waltz took the first giant step of his theoretical career. Even readers who do not wish to take the same step find the path illuminating. Waltz poses two major questions: If bad humans are the cause of war, why is there so much peace? If bad states (or societies, or economies) are the cause of war, why are so many good states implicated in wars? Why does war persist despite variation in the nature of the states and societies that make up the international system? Waltz suspected that classical realism and balance of power theory would tell us something about this — but at that point he could not quite put his finger on it.

The device of "levels of analysis" has become a ready element of our vocabulary about international relations theories. It travels well. Even novices quickly grasp its utility, and find themselves better able to organize both their own and others’ arguments after a brief introduction. More importantly, Man, the State, and War makes the case that there must be something distinctly "international" about international politics, which Waltz suspected could be traced to the absence of a sovereign. The book maps out a space that subsequent theorists, including Waltz, would then need to fill. After we read the book, we know this. Some may disagree with Waltz’s subsequent arguments about the share of international politics that can be explained by "third image" — or system-level — theories, but none can dismiss them.

Waltz’s second contribution to international relations theory is to be found in Theory of International Politics. There, Waltz distills the product of years of thinking about the "third image." He develops the distinctive concept of "international structure" as the distinguishing feature of the international political system. Structure is the minimalist device that captures the basic causal forces and variables of the international political system. Structure is made up of an organizing principle (anarchy) and the distribution of capabilities (polarity). From that, Waltz deduces many of the characteristic patterns of behavior one should find in the relations among autonomous actors. Though Waltz overlooked certain possibilities, such as unipolarity, and left much room for argument about some of his specific deductions, one cannot come away from Theory without a keen appreciation of the constraints and incentives imposed upon states by the condition of anarchy. These lead to the competitive behaviors that are so familiar.

Kenneth Waltz was one of the most influential international relations scholars of the last half-century. Even if he had produced no students, his books would stand as rocks in the road. Nobody trying to understand international politics can avoid them. But Kenneth Waltz did produce many students, who built on his work in their own scholarship, further refining the realist model. Even international relations theories based on other premises must engage with structural realism. Kenneth Waltz found what was international about international politics and built the foundations of the field.

Barry R. Posen is Ford International Professor of political science at MIT and director of the MIT Security Studies Program.

J. Dana Stuster was an assistant editor at Foreign Policy from 2013-2014. Twitter: @jdanastuster

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