LONDON -- The invitations issued at the recent Prague conference to seven former Eastern Bloc states to join the North Atlantic Treaty Organization are a dramatic demonstration of how the world has changed in just a few short years.

The presence of U.S. President George W. Bush at the Prague meeting made clear that the implications involved reach beyond Europe. But, at the same time, it is not churlish to wonder whether the expansion of NATO is not, in some respects at last, a belated recognition of how Europe has changed since the fall of the Soviet empire era rather than the kind of forward-looking breaking of the mold proclaimed by its champions.

With Moscow no longer a military threat, the inevitable question arises about the purpose of NATO. After 9/11, it served as a useful vehicle for Europe to express solidarity with the United States. It could be used in peace-imposing and peacekeeping missions in the Balkans. It formed a bridge across the Atlantic.