Now and then events occur that can be called great turning points or watersheds in history—moments when the world changes and political and cultural currents suddenly halt in their tracks and begin moving in unexpected directions. Columbus's 1492 voyage to the New World, the defeat of the Spanish Armada in 1588, the establishment of the United States in 1776, and the terrorist attacks on New York and Washington in September 2001 readily come to mind. The Japanese sneak attack on the U.S. fleet at Pearl Harbor on December 7, 1941, easily ranks with these epic events in its audacity and impact on subsequent world affairs. In particular, Pearl Harbor drew the United States into a world war; this required it suddenly to begin exploiting its enormous industrial and military potential, which in turn rapidly transformed the face of world politics. In the...