What practical social responsibility do we have to prevent future (and to stop curent) crimes against humanity

Answer 1

We as a country should lead by example by not torturing prisoners, stopping genocide, giving aid to those in need etc.

From a diplomatic point of view it's a win / win situation; The more we work towards correcting atrocities the more allies we gain and fewer enemies. Also, good will is contagious if we as a nation set an example more countries will follow suit.