I always thought that one of the valid explanations (not excuses mind you) for the Japanese military's abuse of POW's, "liberated" citizenry, etc., was the abusive treatment that Japanese children . . . on down to Japanese soldiers received unquestioningly and passed along unquestioningly at the time. Unfortunately, but not too surprisingly, this mindset survived the war in some folks and found fertile ground in certain sectors of the martial arts. This behavioral disorder has even successfully been exported and reproduced in other countries under the guise of 'Traditional Japanese Martial Arts Training.'
Another story, I read but can't remember where, that relates to Peter's post was of O-sensei being brought to military trial for breaking a senior officer's hand. The case was dismissed when it came out that HOW Ueshiba had broken the senior officer's hand was by standing obediently, and obligingly, at attention while the officer in question hit Ueshiba on the head with his fist, thereby breaking his hand! I seem to recall that Ueshiba explained that he had trained his head by beating it against rocks and such, but pleaded innocent to intentionally breaking the officer's hand . . .
Gives a whole new meaning to 愛打、 har, har, har!