Pearl Harbor: December 7, 1941: Pearl Harbor Day: Today is December 7, 1941 and it’s being observed as Pearl Harbor Day. The attack on Pearl Harbor was an unannounced military strike conducted by the Japanese navy against the United States’ naval base at Pearl Harbor.

The Japanese bombing of Pearl Harbor on December 7, 1941, marked the immediate start of World War II for the United States. Their give-it-all-you've-got spirit inspired the regiment's motto, "Go for Broke!," which became the title of a 1951 film celebrating one of the toughest fighting units in the history of the United States Army.

During the final stages of World War II in 1945, the United States conducted two atomic bombings against Japan in the cities of Hiroshima and Nagasaki. On May 10–11, 1945 The Target Committee at Los Alamos, led by J. Robert Oppenheimer, recommended Kyoto, Hiroshima, Yokohama, and the arsenal at Kokura as possible targets