Thanks to the OP for keeping his eye on the inhumanity of the world... it lingers everywhere below the surface of 'civilization.' When I was a grad student in Prague, we took trips to visit the camps and we also took a trip to Dresden... you can still see scorching from the fire-bombing. The degrees of violence and bloodshed, and all the ideological justifications that when along with it was just staggering. I was shaken. And I was no stranger to the stories--my grandpa was a spy and partisan in Greece for the allied side... I have his personal diaries, which have been used by historians. The British Authority even recognized him for his service after the war... hearing about all that, and learning about the atrocities then... (as well as those before and after) is a heavy burden--but nowhere near as heavy as having been there.
As a student, I visited Terazin--it was the "good camp" the Nazis would show the Red Cross and the like, to demonstrate that they were not horrible after all... well, let me tell you--I walked into a cell meant to create total darkness... I walked to the back corner and was engulfed in darkness, and that was with the door open. It was terrifying... in 1998... imagine as a prisoner. And that was just a holding cell. Upon seeing the ovens used for cremation, and realizing that our guide's grandfather was one of the prisoner's in the old pictures on the wall... well, I lost it a bit.
These days I teach political philosophy and theory at a major university--one of my courses is about ideology and conflict (freshman level)... and we read, study, discuss these things all the time. It never gets easy.
Carry on brothers...