USA HISTORY

Detailed explanation-1: -On December 7, 1941, following the Japanese bombing of Pearl Harbor, the United States declared war on Japan. Three days later, after Germany and Italy declared war on it, the United States became fully engaged in the Second World War.

Detailed explanation-2: -The Japanese attack on Pearl Harbor on December 7, 1941, ended the debate over American intervention in both the Pacific and European theaters of World War II. The day after the attack, Congress declared war on Imperial Japan with only a single dissenting vote.

Detailed explanation-3: -During World War II, the United States began to provide significant military supplies and other assistance to the Allies in September 1940, even though the United States did not enter the war until December 1941.

Detailed explanation-4: -The United States entered the second World War following the unprovoked attack on Pearl Harbor by Japan on 7 December 1941.

Detailed explanation-5: -Larger historical forces eventually brought the United States to the brink of World War II, but the direct and immediate cause that led it to officially entering the war was the Japanese attack on Pearl Harbor.