Well you can argue either side on this. You can say it was a wise decision because America was going to enter the war eventually anyway and it was wise to strike first and cripple the Pacific Fleet, prolonging the amount of time it would take for the American force to reach full power in the Pacific. You could also argue that it was not a wise choice because Yamamoto stated before the Pearl Harbor attack that he knew we were too strong to defeat. So maybe if Japan hadn't attacked the US at Pearl Harbor, we wouldn't have entered the war until it was too late and the Axis powers were too strong.
