There's a very good film about that, called City Of Life And Death: http://en.wikipedia.org/wiki/City_of_Life_and_Death (about the "rape of Nanking", 2nd Sino-Jap war.) Not something i'd want to watch again in the foreseeable future, but once is an absolute must. A really good film.
This ability for social units to see other social units as subhumans is not uncommon.
Social conditioning can make the constituents of a society find acceptable the rape, torture, genocide, and general schadenfreude against other societies. What we see here is herd mentality at work. The phenomena of herd mentality is how Germans under the Nazis felt exterminating the Jews was 'just,'
'Hive mentality' is even more accurate than 'herd mentality' i think, but basically the same concept. Reminded me to one of my old PF replies (thread was 'Empathy in action'; i copy it here, too lazy re-typing:
[quote="Twentycharacterslong"] I wonder if collective empathy starts revolutions. [/quote]
[quote="wooster"] Not in a welfare country, but in a sufficiently corrupt & oppressive regime with the resulting poverty, yes. See all revolutions across the Eastern bloc, from '56 to '89, & etc.
Collective empathy also starts things like the Holocaust, so you gotta tread extremely carefully with anything collective. "Collective" has the effect of eliminating individual guilt and personal responsibility/conscience, so even impeccably upstanding citizens start burning Mr Kohn their grocer in the gaschambers cuz everyone & their maiden aunt is at it, therefore it has to be the right thing to do. [/quote]
( or currently HK, Ukraine & so forth)
In short, 'society' at large is better handled with due suspicion. When "collective" breeds with ideology (of any kind) that's invariably bad news.
Perhaps this is why we have yet to see one openly agnostic or atheist U.S. president.
I think i've read somewhere that it's in the USA constitution that the president has to be Christian, no? (I remember laughing in disbelief at the time, i mean for fucks sake... )