Ever heard of the Nanjing Massacre? Unit 731? The Bataan Death March? It's not like the Japanese were innocent in World War II, either.
By the way, your obvious hatred for Americans is a real great display of immaturity. I've seen your type plenty before - the kind that like to lump people into groups and make biased judgments against them. Clearly you've let stereotypes cloud your judgments. Americans can be a loud, uncultured bunch - there are more of those types of people in America than in other cultures/countries, but they are by far not the norm here. Grow up, mate.