I suppose the sadist who ran a death camp is in a way not as disturbing as the scheduler who made the trains to the death camp run on time. Relatively few people are like the sadist, even in troubled societies, but millions of normal people can be conditioned to not ask questions and dutifully make the trains run on time.
One thing that happens in all totalitarian countries is that people are isolated and conditioned by propaganda. So if one person has the normal thought that the government is monstrous, he quickly corrects himself because surely, he is the only person to have such forbidden thoughts and something must be wrong with him. He then has to prove to himself that he is "normal" by telling himself that he loves Big Brother all the more. Less principled people partake in or profit from the government's crimes so that if one compromises just a little bit, then one has bought into the system and once "invested," one becomes more and more corrupt.
And yes, EVERY country has psychopaths, it's just that in many countries the head of state is a psychopath. Liberals don't understand that.