If Pearl Harbor had not been attacked in 1941, would not have entered the war as soon as we did. We still would have eventually entered the war, and we still would have won, but I am not sure we would have won as fast as we did, because we would not have been so determined to win.

The attack on Pearl Harbor energized the nation into the war. If the attack had not had happened, that would not have happened, and who know how it could have gone.