Twice within twenty-five years, Britain sent an ultimatum to Germany that resulted in war. A vast literature has illuminated the long-term and short-term causes of Britain’s actions, and the number of books and articles continues to increase. In 1972, I gave a seminar paper comparing and contrasting the state of public feeling in July 1914 and in September 1939. In the case of the former, which was my main subject, I looked at the change in British sensibilities since the turn of the century, which I thought pertinent to the public acceptance of war despite the number of those objecting to engagement in a continental conflict. The actual response to the decision for war in July was dealt with in a more cursory fashion. After some summary remarks about the effects of the Great War on public perceptions of war and an examination of the deteriorating international situation in the 1930s, which challenged the movements for disarmament and collective security, I focused on the decision for war in 1939 and the reactions of the political elite and the public to its outbreak.

No scholar, historian, or policy-maker wishes to dispute the role that power plays in foreign affairs. From Thucydides to modern international politics, the power of a state has influenced its position and success in dealing with other countries. But the calculus of “power” is not the be-all and end-all of national policy in international relations. Countries are prompted to act as a result of their economic circumstances, their moral codes, and their institutional setting (reinforced by domestic politics) as much as by their position in the power hierarchy. Leaders frequently have ambitions that range beyond the limits that power technically permits. Sometimes, decision-makers also minimize their involvements owing to the pressures of internal factors. Sustained by such pressures, international institutions, ideologies, and recognized legitimacies temper and channel the pursuit of influence. Sometimes leaders strive to protect their own position against domestic opponents, even when their country might lose a war in consequence. The definition of the state's situation in foreign affairs also conditions outcomes: is the state rising or declining? Does action have to be taken to prevent further decline? In regard to each of these factors, the authors of this volume have shown in case after case that countries do not restrict their policies to what their “power line” apparently mandates – the relative position they occupy vis-à-vis other major nations in the power hierarchy. Instead they chart their own course – influenced by external pressures, but not determined by them.

For many years, the dominant approach to the study of international relations has been that of structural realism. Because this theory has such a long pedigree, there is a great divergence of views among those who call themselves or are called “realists” or “neorealists.” In order to give shape to this chapter, I have arbitrarily selected what I consider to be the main features of the realist case, knowing that many variants of the model exist. Realists begin with the assumption that states live in an anarchical international environment where there is no authority above that of the state. As a result, great powers, usually the focus of realist theorists, must rely on “self-help” to survive. They seek to maximize their power as against other states, though occasionally they will try to achieve absolute power without regard to the other players in the system. States which try to increase their power necessarily make other states feel more insecure and they will respond by adopting strategies to enhance their chances of survival. Structural realists or defensive realists, following Kenneth Waltz, argue that when great powers act aggressively, their would-be victims try to balance against the aggressor and check its threat to their survival. The anarchical conditions of the international life encourage states to behave defensively so that they can protect themselves and try to maintain their power positions.

Introduction

When a major power acts aggressively and unpredictably, opponents often are nonplussed. The targets of aggressive action first interpret the move as a deliberate challenge, and are tempted to adopt an offensive response. But, they hesitate to respond until they understand why the opponent felt impelled to issue the challenge. Chairman Nikita Khrushchev of the Soviet Union placed “offensive” missiles in Cuba, although President John F. Kennedy had explicitly warned him not to do so. When the missiles were detected and the president informed on October 16, 1962, JFK reacted explosively. “He can't do this to me,” Kennedy said (in more graphic terms than reproduced here). Kennedy's advisers initially interpreted Khrushchev's move as a completely illegitimate and unparalleled action in terms of Soviet foreign policy. No Soviet leader had ever placed such missiles in the Eastern European satellite countries – how could they station them ninety miles off the coast of the United States? From Khrushchev's point of view, however, while the placement was abrupt and unprecedented, it was also a symmetrical response to American stationing of Jupiter missiles in Turkey near the southern border of the Soviet Union. The Soviet missiles were also sent in reaction to US threats to Cuba which were even more compelling than any Russian pressure on Turkey. “What was sauce for the goose was sauce for the gander,” Khrushchev reasoned.