As the Cold War wound down in the early 1990s and the threat from the Soviet Union receded, the reason why the North Atlantic Treaty Organization (NATO) was created disappeared. But bureaucracies die hard, and bureaucratic and political inertia are often hard to overcome. An alliance established to contain the Soviet Union needed a new purpose, and like other going concerns and political organisms, NATO would either expand or die. So it expanded. And it began to expand at the same time that the United States was urging Russia to join the West in a "partnership for peace," and to...