Answer:
The direct cause was the Japanese bombing on the American fleet in Pearl Harbor, Hawaii, on December 7, 1941
Step-by-step explanation:
The USA did not enter the war initially. The military history of the United States in World War II covers the war against Germany, Italy, and Japan, starting with the 7 December 1941 attack on Pearl Harbor. The war began with Nazi Germany's attack on Poland in September 1939, the United States did not enter the war until after the Japanese bombed the American fleet in Pearl Harbor,