To some extent I agree, but we hit quite a problem when we go back in history to justify epithets. The main issue is where does it all start? For example, the current issues with ISIS can be laid squarely at the feet of the English monarchy, since it can be argued it was the crusades which effectively ignited the Islamic hatred of the West.
I agree there seems to be a cultural ethos of causing pain in the Japanese culture and you're quite right about some of the horrendous acts of cruelty inflicted, particularly on the Filipinos. But what about the Germans in WWII? What about the Roman Catholic Church during the Inquisition? Do we condemn the Turks, the Germans, the Italians, the Spanish because of historical acts of savagery?
I suspect all we can do is live in the present and determine how we treat our fellow man according to our own codes of ethics.