Almost as soon as the attacks occurred, conspiracy theorists began claiming that FDR had prior knowledge of the assault on Pearl Harbor. Others have claimed he tricked the Japanese into starting a war with the United States as a “back door” way to go to war with Japan’s ally, Nazi Germany. However, no document or credible witness has been discovered that proves either claim. Most scholars view Pearl Harbor as the consequence of missed clues, intelligence errors, and overconfidence.
On December 7, 1941 debate over American involvement in World War II ended abruptly. Isolationist sentiment disappeared and the nation emerged united and determined, in FDR’s words, to “win through to absolute victory.”