But it was the combination of the difficulty of saying no to authority and probably peer pressure , together with the reasonable possibility they'll be sent to the front lines (not even as a punishment , but because that's what men did back than).
If it's a choice between him and me, I choose me.
If it's a choice between those ten people and me, I probably choose me.
If it's a choice between a n+1 people and me, I guess I've already done n, what's another one?
Acknowledging that there is a difference between being sent away to war and certain death. That there's a difference between 1 more person and a hundred. I believe that far more people than we'd like to admit would just follow orders.
The quote was "one thousand and one is still only one thousand" from a poem about a concentration camp (https://en.m.wikipedia.org/wiki/Szebnie_concentration_camp)
There may be things that are not understandable, but, when we give it our best shot we can say we tried.
In many cases, I imagine the SS officer may have had a gun pointed to his head himself. That certainly was the case in Cambodia. If a soldier didn't kill someone who he was ordered to kill, he would be shot himself.
If we can keep tensions low and communicate better I believe we can at least forestall further world wars.