A number of factors have obscured details—big and small—from that day. For example, the surprise of the attack complicated eyewitness accounts. Secrecy shrouded the active war effort on both sides. And, in the aftermath, the United States rushed to rebuild its naval power in the Pacific with the greatest maritime salvage project in history, which returned all but three of the damaged ships to service. This effort begins to explain why there are few archaeological sites directly tied to December 7."

No, says Roosevelt biographer Jean Edward Smith.

"He was totally caught off guard by it," Smith says. "The record is clear. There was no evidence of the Japanese moving toward Pearl Harbor that was picked up in Washington.""

It has since been implied that the reason Hawaii was not on the alert was that Washington thought the Japanese would not attack there. That suggestion points up very neatly the crucial issue. For the opposite was true—Washington thought the Japanese would not attack Hawaii largely because it believed Hawaii was alerted and prepared."