CrowTRobo: The Holocaust.
ChrisSD: Ahh I thought he meant to include that with "basically all of WW2 is unbelievably nightmarish". My mistake.
True, but the Rape of Nanking and Unit 731 were both from WWII. I figured if you were going to list specific atrocities from WWII, you would list the worst one.
Call me weird but that is actually what fascinates me about WWII - because I can't wrap my head around how such events actually occurred and how people degenerated into beasts so quickly.
My professor of Political Theory was an admitted opponent of the state system, so he was a bit biased, but made some good arguments for putting blame on the nation state system.