USA HISTORY

Detailed explanation-1: -On December 11, 1941, Italy declared war on the United States in response to the latter’s declaration of war upon the Empire of Japan following the attack on Pearl Harbor four days earlier. Germany also declared war on the U.S. the same day.

Detailed explanation-2: -On December 11, 1941, Germany and Italy declared war on the United States.

Detailed explanation-3: -On December 11, 1941, three days after declaring war on Japan, the House approved declarations of war on Germany and Italy; earlier that day Germany and Italy had declared war on the United States.

Detailed explanation-4: -On the morning of December 11, during a rambling speech at the German Reichstag, Adolph Hitler declared war on the United States in accord with the Tripartite Pact of September 27, 1940; Italy followed suit.