What significant event does December 7th (December 8th in Japan) commemorate?

December 7th commemorates the Attack on Pearl Harbor, which occurred in 1941. This surprise military strike by the Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, led to the United States' formal entry into World War II the following day. It was a pivotal moment in history as it shifted public opinion in the U.S. towards supporting involvement in the war. The attack resulted in significant loss of life and damage to the Pacific Fleet, marking a decisive turning point in military strategy and global alliances during the conflict. The historical ramifications of this event have been profound and continue to influence U.S. foreign policy and military strategy to this day.