The Prize: The Epic Quest for Oil, Money, and Power

by Daniel Yergin

At a fundamental level, each side had underestimated the other. Just as the Japanese did not think the Americans were technically capable of cracking their most secret codes, so the Americans could not conceive that the Japanese would be able to mount so technically complex an operation. Indeed, in the immediate aftermath, some of Roosevelt’s senior advisers believed that the Germans had orchestrated the assault; they assumed the Japanese could not have done it alone. And each side mistook the other’s psychology. The Americans could not believe that the Japanese would do something so daring and even reckless. They were wrong. And the Japanese, for their part, counted on Pearl Harbor to shatter American morale, when, instead, the attack would revivify national morale and swiftly unite the country. That was a much greater error.