Japanese-American Incarceration During World War II In his speech to Congress, President Franklin Delano Roosevelt declared that the Japanese attack on Pearl Harbor on December 7, 1941, was "a date which will live in infamy." The attack launched the United States fully into the two theaters of World War II – Europe and the Pacific. Prior to Pearl Harbor, the United States had been involved in a non-combat role, through the Lend-Lease Program that supplied England, China, Russia, and other anti-f