History is not going to find it easy to render a full judgment on the Second World War. The impact of the technological developments which that war stimulated is still working itself out. These developments alone have set to the politicians of various countries a series of problems which demanded action and which required a more complex, sustained intellectual effort than was needed in earlier times. The more advanced and more powerful the country, the more the problems arising from technological development, especially in weaponry, placed themselves in the centre of attention. For a full decade after the end of the war, it was generally thought that the bipolar distribution of power was a lasting phenomenon. The second postwar decade produced some evidence that this might not be so, but even now no one can be quite sure what qualifications or exceptions to bipolarity are significant today or will be in the future. The decolonisation process, attended by the emergence of many new, for the most part modernising, states and paralleled by the restructuring of European politics, clearly is one of the major phenomena of the period. Here, too, the future is obscure. Throughout the period, there has been a pervasive uncertainty as to what cultural and social values the world's peoples would subscribe to and what political leadership they would follow.