For more than thirty years we have grown accustomed to thinking of the history of our times as ‘post-war’, the war itself standing for most people as a great barrier reef between an international order still dominated by the European great powers and the modern world of nuclear technology and super-power rivalry. In international relations some periods are demarcated by events of such momentous significance that their contours are obvious even to contemporaries. But there are other times when a combination of developments will alter decisively the major relationships involved in international politics, without any such obvious or cathartic bieak with the past. It is our belief that the period documented in this volume is of this kind. Between 1968 and 1975 a series of developments in the relations of the major world powers transformed the arrangements by which they had been governed since the end of the Second World War. The assumption on which the documents have been drawn together is that these years marked a definitive transition in the history of the contemporary states-system, after which it could no longer be described, except in a purely literal sense, as ‘post-war’. It was during this time that the great powers of the wartime alliance against the Axis finally evolved a kind of peace agreement, whose absence had shaped the basic pattern of their relations since 1945. The cold war finally came to an end and in consequence the framework of great-power relations was changed.