You miss my point, I find it hard to grasp how a modern society with mass communication can debase itself.
And yes the Treaty of Versailles did create a vacuum for the rise of Nazism.
But it doesn’t get away from the horror and shear depravity, perhaps we see these kind of acts belonging to another time or place (yes both wrong I know) but where “intelligent ” people come from, it is an even darker place to look into.
If it can happen in “modern Europe” than no one is safe from fanaticism and the depths of where humanity can end up.