Why did the united states finally enter world war ii?

germany invaded poland.

the soviet union refused to pay back debts it owed.

italy took territory in ethiopia.

japan bombed pearl harbor.

The correct answer to this question is Japan bombed the Pearl Harbor. The time when Japan bombed the Pearl Harbor got the United States to finally enter the war. Although the war has begun with the Germany's invasion of Poland, the United States agreed to stay out of it. However, everything changed on December 7, 1941, a date that every American will never forget. 

If this is a true or false question i would say true