To those living through it, each era seems unique. But I suspect that even later generations will share this perception of the 1990s. Rarely if ever has world politics been fundamentally reordered without a major war. Of course, in some sense we have witnessed a major war, and the Soviet Union lost it. But the differences between a conflict that was prolonged yet bloodless—at least for the major protagonists—and a “normal” war are very great. This is even true for the victor. While the Soviet Union confronted the internal turmoil and revolution that often accompanies a military defeat, the United States, even with its triumph in the Gulf war, does not appear to have the strength, will, or vision to establish a “new world order.” The structure of power in the post-Cold War world also appears to be unique. Indeed, we cannot even characterize it in terms of the system's polarity, the concept of which political scientists are so enamored. Is the system unipolar because the United States is so dominant, bipolar because nuclear weapons are still concentrated in two hands, tripolar because we can anticipate the emergence of a united Europe that will take its place alongside the two former superpowers, or multipolar because so many forms of power-especially economic power-are now widely dispersed? The coming era also seems odd because it is hard to locate a main axis of conflict. In the past, the two leading states usually were adversaries because each constituted a potential if not actual menace to the other.