How many hours before the United States did Great Britain declare war on Japan ?
During a radio broadcast on June 29 , 1941 , one week after the Nazi invasion of the Soviet Union , Hoover disparaged any " tacit alliance " between the U.S. and the USSR by saying:When the United States entered the war following the December 7 , 1941 , Japanese attack on Pearl Harbor , Hoover swept aside all feelings of neutrality and called for total victory .