When Japan took over Indochina in 1941, the US froze all Japanese assets and set an embargo on Japan, and that cut off of oil hurt the Japanese economy. Under the rule of prime minister General Hideki Tojo, Japan set a deadline that if the US didn’t yield by December of that year, Japan would attack, although it was thought by the US after cracking a Japanese diplomatic code that they would go for Dutch or UK possessions. On December 7, 1941, Japanese dive-bombers attacked the US Naval Base of Pearl Harbor on the Hawaiian island of Oahu, killing over 2400 Americans. FDR called it “a day which will live in infamy” and Congress declared war the next day.