Originally part of a comment by Golgafrinchan Captain on They were essentially without any relevant experience.
When I was growing up, my parents had a friend who had been a Nazi is WW2. It wasn’t something he really talked about but, through the years, I gathered some details from him and some more from his children. They thought they were the good guys, doing what needed to be done to protect themselves and the world from an imminent threat. It scares the crap out of me that our brains can make that kind of rationalization, but they can.
He was captured quite early and kept in a Canadian POW camp. The moment he realized how horribly wrong he had been is when he got to the POW camp and was actually treated well. The enemy he thought he was fighting would never show compassion to captives. That’s what’s so horrible about things like the US torture program; it confirms the beliefs of “the enemy”.
When Bush Jr.’s Iraq war started, it really messed with my head. Many of the things I heard coming out of the States reminded me of the things that had convinced my parents’ friend that they were on the side of good in WW2. Note: this is not to say that the US’s current actions are anywhere near as horrible as some of the things done by the Nazi’s, but it’s walking the same path. Also, plenty of comments by US citizens were/are just as horrible (“nuke all the sand-n***ers”, “savages who don’t deserve to live”, etc.). To be fair, Canada also has it’s share of such assholes but I think they are tolerated much less.