It's a delicate issue. Nazis are portraid by the media as insane, ultra-evil people who are better off dead and we shouldn't even think twice before killing one of them - I mean, look at the Indiana Jones movies. Japanese soldiers are hardly portraided like this, mostly because they didn't have a direct participation in the holocaust. Also adds to this the hiroshima and nagasaki bombings, and the fact that the Japanese seemed more "open" and "friendly" outside war times. It's a little bit shocking to play a videogame where what you have to kill isn't a: a) nazis, b) fictional evil criminous people, c) aliens, or d) a fictional faceless evil nazi-like army. That's why I don't get shocked with WW2 nazi-related war games, but a Vietnam game shocks me completly - I don't know why people would play a game set in the Vietnam war.