What Bernard Brodie said about nuclear weapons in 1946 continues to be true: The most important thing about nuclear weapons is that they exist and are terribly powerful. This was true in both the Cold War and the subsequent era. Although the situation has changed a great deal, there are striking continuities, especially in American attitudes and policies. Most obviously, the United States has consistently opposed nuclear proliferation, with only a very few exceptions for its closest friends. Second, the debate within the United States about the role of nuclear weapons has been altered only slightly by the end of the Cold War. The fundamental division between those who see nuclear weapons as having a revolutionary impact on world politics and those who do not continues. Trump’s Nuclear Posture Review makes arguments that are remarkably similar to those made under the Raegan administration. In parallel, the arguments made against Anti-Ballistic Missile (ABM) systems today are quite similar to those advanced during the Cold War, despite the radically changed conditions. This indicates that ways of thinking about nuclear weapons have become deeply engrained.

For diplomatic historians to delve into the sub-field of Political Science that studies International Politics or Relations (terms I will use interchangeably) is to enter a world that is both familiar and different. Indeed, it is the similarities that make the differences so jarring. Just as Dean Acheson expressed his bemusement at discovering that International Relations (IR) scholars treated him as an “independent variable,” so do many historians find distasteful the notion of variables, especially ones labeled as independent (causes) and dependent (effects), studying historical events as “case studies,” seeking generalizations as wide-ranging as possible, valuing “theoretical parsimony,” with its emphasis on deploying as few independent variables as possible, and comparing cases that are dissimilar in many ways. But I believe that the very differences between the two fields make interaction potentially fruitful if historians are willing to (temporarily) suspend disbelief.

Obviously, the field of IR is too large to completely cover here, and my survey will be skewed toward international security rather than political economy, international organizations, and transnational trends and flows. In the course of this, I hope to make clear why a chapter on IR theory in some ways fits awkwardly with a book on approaches to the history of American foreign policy.

I will proceed by outlining two related ways of dividing the theoretical approaches to IR: the first between the orientations of Realism, Liberalism, and Social Constructivism, and the second sorting according to whether the main independent variables are located at the level of the individual, the state, or the international system, which lends itself to a discussion of how IR uses comparisons to try to pin down causation. I will concentrate on theories about relations among the most powerful states, which leaves out many important subjects but is most relevant to arguments about American foreign relations.

REALISM

The best known approach to IR is Realism, which comes in several flavors: classical, neoclassical, offensive, defensive, and structural. All share the common starting point that states are usually the main actors in international politics, that considerations of power and security are paramount, that states are (and should be) guided by the national interest as contrasted with sub-national or supra-national interests, and that the world is dangerous both because human nature is malign – or at least has a malign streak in it – and because this realm, unlike domestic society, …

To say that the world is now unipolar is neither to praise American power, let alone its leadership, nor to accuse the United States of having established a worldwide empire. It is to state a fact, but one whose meaning is far from clear, as we have neither a powerful theory nor much evidence about how unipolar systems operate. A central difficulty for sorting this out entails determining the extent to which behavior and outcomes we have seen stem from structure, rather than from other levels of analysis, such as idiosyncratic aspects of the international environment, the American domestic system, and the role of individual leaders. How might the system function if the unipole were Nazi Germany, Stalin's USSR (or Brezhnev's), or a traditional autocracy? Or if it were the United States in a different era? There would surely be major differences, but we should still start our analysis with structure. In fact, this takes us quite far and, as well, to some unexpected places. Realism indicates that the unipole is likely to be difficult to restrain, no matter how benign its intentions or domestic regime. Furthermore, it is far from clear that it should seek to maintain existing arrangements. Both normal ambitions and, in the current context, American values and beliefs may lead the superpower to seek to change the system rather than preserve it.

World politics and the study of world politics

Academic analyses are influenced both by events in the world and by scholars’ political outlooks and preferences. The growth of realism was obviously entangled with the Cold War; revisionism about the origins of this conflict was sparked by the war in Vietnam (although this approach in fact was unable to explain the self-defeating American policy); the subfield of international political economy (IPE) developed rapidly in the wake of the American abandonment of the gold standard, the growth of OPEC, and the oil boycott following the 1973 Middle East War. The other side of this coin is that things that are not happening lead to subjects being ignored. The role of religion in international politics, for example, received little attention until the emergence of “political Islam.” Similarly, civil wars are important and interesting analytically but were intensively studied in the US only during the Vietnam conflict (when the subject was considered under the topics of “counter-insurgency” or “internal war”), falling back into quiescence until such types of conflict returned in the 1990s.

The question for this chapter is how Soviet and American national identities shaped and were shaped by the Cold War. Defining identity is not easy, however. Is it the same as self-image or self-perception? How does it relate to ideology and political culture? Can we treat national identity as singular in the face of internal differences? What evidence can establish the content or even the existence of identities, and how do we go about determining their causes and effects?

Although in the end perhaps we have to settle for the Potter Stewart definition of knowing it when we see it, more formally national identity can be seen as the set of values, attributes, and practices that members believe characterize the country and set it off from others. Identity is the (shared) answer to central if vague questions: Who are we? What are we like? Who are we similar to and different from? Identity is at work when people say “We must act in a way that is true to what we are,” as Jimmy Carter did in his 1978 state of the union address when he declared that “the very heart of our identity as a nation is our from commitment to human rights.” Identities thus carry heavy affective weight, and this helps explain why scholarly arguments about the Cold War are often very bitter because the stakes include what the Soviet Union and the United States are like or should be like.

Introduction

The challenger faces a much stronger adversary and is frustrated by its inability to protect itself and change the status quo. Blocked from advancing its cause and enraged by the adversary's hostile if not aggressive actions, it hits upon a clever if desperate move. The adversary's superiority makes it overconfident and the challenger proceeds in secret, disguises its actions, and does what is believed to be unlikely, thus enabling it to put its forces in position without being discovered. By taking actions that bear some resemblance to what the adversary has done, the challenger gives itself added legitimacy. Nevertheless, when the adversary discovers what is happening it reacts very strongly, and the rest of the world sides with it. After an exchange of nuclear threats and conventional maneuvering, the challenger is forced to withdraw, humiliated and with little to show for it. One result is that the challenger's leader is overthrown. The world has come uncomfortably close to a nuclear exchange, but years later we still debate the motives on each side, the nature of the interaction, the relative importance of conventional and nuclear arms, the actions of third parties, the role of intelligence, and whether a better diplomacy could have diffused the crisis.

At the end of the century, the United States finds itself in a place that is surprising in many respects, but that is surprisingly familiar in others. Indeed, much more than anyone had reason to expect during the Cold War, the American security position resembles what it was at the start of the century while the world has become more compatible with American values. Of course this does not guarantee that the next century will turn out well. Henry Luce said of the twentieth century: “No other century has been so big with promise … and in no one century have so many men and women and children suffered such pain and anguish and bitter death.” The first part of the statement clearly applies to the century we are entering; while appreciating the frequency of overoptimistic predictions, I doubt if the second part will.

It is a commonplace that “in the twentieth century, scientific and technological innovation increased at an exponential rate. … The Industrial Revolution extended over generations and allowed time for human and institutional adjustment. The Computer Revolution is far swifter, more concentrated, and more drastic in its impact.” Almost everyone agrees that change has been proceeding at an accelerated rate. Furthermore, it is usually argued that change is greater and more rapid in domestic than in international affairs. Our everyday lives and societies have been revolutionized by technological change and economic growth while international politics maintains its basic consistency, in large part because it remains a system of self-help and anarchy in the sense of absence of government.