On December 7th 19141, the Imperial Japanese Navy Air Service launched "Operation AI", a pre-emptive strike against the US Pacific Fleet stationing at the Hawaiian base of Pearl Harbor. On that day - "the day of infamy" on Roosevelt words - the Japanese damaged seriously all the battleships and sunk some, almost a hundred of US aircraft got destroyed and more than two thousand men were killed. The Japanese thought to have put the United States off from the chance to interfere with the establishment of the Greater East Asia Co-Prosperity Sphere. What they did, on the contrary, was to wake a sleeping bear. 

December 7th didn't mark the supremacy of the Japanese Empire, it marked the beginning of its end.