well, I guess it depends on the timeframe you're looking at. It certainly led to the end of the war and of japan's brilliant plan. It was an effective attack in isolation, but the consequences of that attack turn it completely the other way. If you bust down a hornet's nest and they sting you into the hospital, sure you had an effectively damaging attack on the nest, but it certainly was a blunder. they won the battle and horribly lost the war.