Why did the United States enter World War II?

Question

A. It did not agree with British politics
B. It wanted land in Europe
C. The Japanese attack on Pearl Harbor
D. It wanted the economic opportunities that war could bring.

Answer 1

C. The Japanese attack on Pearl Harbor

The United States entered World War II primarily as a result of the Japanese attack on Pearl Harbor on December 7, 1941. This surprise attack led to a formal declaration of war against Japan, and subsequently, Germany and Italy declared war on the U.S., bringing America fully into the conflict.