December 7 - 1941 - The Attack on Pearl Harbor
When the Imperial Japanese Navy attacked the United States Naval Base at Pearl Harbor, the real issue from the point of view of the American leadership was that there was no declaration of war or hostilities before the attack. Most Americans were shocked at the massive loss of life and Navy ships. All of this would lead to America's immediate entry into World War II, against both the Empire of Japan and their allies Germany and Italy. While Japan succeeded with their immediate goals at Pearl Harbor, the attack was largely a huge tactical mistake. The Japanese Navy never made it further than Hawai'i, or even made it back there. America would eventually roll back the Japanese Navy to Japan itself and win in both theaters of the war, all of which was the result of the attack on Pearl Harbor.