December 7th, 1941 is remembered as the day the Japanese military launched a surprise attack on the American fleet at Pearl Harbor.
This was the inciting incident for the USA declaring war on Japan. Germany, Japan’s ally, then declared war on the USA.
Photograph of Battleship Row taken from a Japanese plane at the beginning of the attack. The explosion in the center is a torpedo strike on the USS West Virginia. Two attacking Japanese planes can be seen: one over the USS Neosho and one over the Naval Yard. (Source: Wikipedia)