Answer:
At the outset of World War II, the United States chose to remain neutral, in line with its longstanding policy of avoiding foreign entanglements. President Franklin D. Roosevelt supported the Allies and provided aid to Britain and China, but he also faced strong isolationist sentiment among the American public and political leaders. The event that ultimately pulled the US into the war was the surprise attack by the Japanese on the American naval base at Pearl Harbor, Hawaii, on December 7, 1941. The attack killed over 2,400 Americans and led to a declaration of war by the United States against Japan the following day, as well as the entry of the US into the broader conflict against the Axis powers.
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