December 7th, 1941. Just before dawn, 270 miles northwest of Oahu, Hawaii, 181 Japanese fighters and bombers prepared to take off from six aircraft carriers. They were the first wave in what would be a massive and devastating surprise attack on the United States Pacific Fleet moored at Pearl Harbor.

In the Fall of 1941, the naval and air base at Pearl Harbor and the escalations on Oahu, represented the greatest concentration of American military power in the new world.

Though they had not delivered the finishing stroke at Pearl Harbor, the Japanese had put the Americans and the British on their heels in the Pacific. The Japanese Navy had been at war constantly since 1937, and it was in prime condition for war.

Japanese admirals stuck rigidly to the view that submarines were first and foremost an adjunct to the battle fleet. Even when they were forced to use the boats to move soldiers and supplies during the Pacific Campaign they still held to this outdated view. This abdication by the Japanese submarine arm was a prime example of a lack of flexibility in Japanese strategic and tactical planning.

Even though Japanese war plans were habitually best-case and not worst-case, the military junta on the home island were so surprised by the scale and speed of its successes in the first four months of the war in the Pacific, that it was wondering what to do for an encore. What was thought in advanced to require six months had only needed three.