THE 50th anniversary of the United Nations is an appropriate moment to look at the state of different regions of the world half a century after the end of the last great world conflict. So today we start a series of editorials by considering western Europe, which was lying in ruins in 1945, but has, since then, enjoyed its longest period of peace in modern times. With peace came years of relative prosperity and, above all, the construction of the European Union. Whatever Britain's reservations, Europe's mainland nations see no other way forward than this growing group which symbolises the end of centuries of military and political conflict. Yet for all its progress since 1945, western Europe is an uncertain place these days. Politicians are deeply distrusted. They are seen as out of touch with the problems of the end of the century and, in too many cases, tainted by corruption. As if this was not enough, the great European project set out at the Maastricht Conference at the beginning of the decade has run up against the barriers of reality with few countries able to meet its tough economic criteria. Meanwhile, the conflict in the former Yugoslavia has created deep embarrassment as western Europe tries to find its place in the post-Cold War world. The ultimate irony is that the great winner of the post-war period is the nation which was on its knees in 1945. Given its past, Germany has genuine hesitations about taking a leading international role. But the combination of economic success, stable leadership and size mean it has emerged as the dominant power. Chancellor Helmut Kohl has just told Germans to shake themselves up, take more risks and show greater leadership. He might have been speaking to western Europe as a whole. Viewed from Asia, it is easy to see the region as a protectionist bloc sheltering its uncompetitive industries from the real world. It will be up to Europeans in the coming years to show they can play a major role politically and economically alongside North America and Asia. So far, they are not doing a very convincing job.