Okay i get what you mean. The soldiers from the west have a honorable sense of conduct. They don't kill for fun. But you are pointing a specific incident, not the whole statistics (Check out allied war crimes on wikipedia). I am not sure whether Japs or Germans have their honor too. But i am sure there were "good" people there. Like in the North African war, Erwin Rommel had a reputation for conducting a clean war.

I am not sure whether you watched Clint Eastwood's letter from Iwo jima, but it did show that Japs had some honourable soldiers. Fiction or not, he seems to be quite an influential film-maker. Not sure whether it is real since I have never fought in war.

Maybe because i am an Asian, and a Chinese (not mainland) and we believe in Ying and Yang philosophy -- evil and good are both sides of same coin.