The date December 7, 1941, is often marked by the surprise military attack on Pearl Harbor by the Japanese Imperial Navy. This event led to the United States' formal entry into World War II. Prior to the attack, the U.S. had maintained a stance of neutrality, but the assault resulted in significant loss of life and damage to the Pacific Fleet. As a consequence, on December 8, President Franklin D. Roosevelt delivered his famous “Day of Infamy” speech, asking Congress for a declaration of war against Japan, which dramatically altered the course of the war and U.S. foreign policy.