These American misjudgments and mistakes played right into the hands of Japanese war planners and ensured that the attack would be a devastating surprise. At 7:02 A.M.Hawaii time on the morning of December 7, an army air corps radar operator detected a large group of planes approaching Oahu from the north at a distance of about 137 miles. The operator quickly telephoned his duty officer, Lieutenant Kermit Tyler. Tyler knew that a flight of American B-17 bombers had left California on December 6 and were due to arrive that morning on Oahu. Thinking that these were the planes that had been sighted, he told the radar man, "Don't worry about it."

Tyler and his co-workers had no way of knowing that the approaching planes were the Japanese attack craft that had followed their lead pilot, Fuchida, to Oahu. At about 8:00 A.M...