Never before in its history has the United States enjoyed such a favorable strategic environment as it does today. There are few deadly enemies anywhere in sight. The U.S. military budget surpasses that of China, Russia, and the five Western European powers combined, and U.S. military capabilities are well ahead of those of any ally or potential adversary. America\u27s booming economy and domestic social arrangements—with crime and unemployment down to the levels of thirty years ago—are a puzzle to those who, as recently as a decade ago, were predicting inexorable American decline. Such a surfeit of U.S. power and prestige, and the apparent absence of any significant obstacles to it, have prompted many to argue that this is a unique histori...