The idea of "Hogan's Heroes" resonating at all is still utterly bizarre to me, given the legacy that we have now of WWII Germany, but I guess with some countries, gentlemen's rules of war were still a thing.

The Russians had a reputation for brutality, and so were considered by the German army to be undeserving of the gentleman's rules of war. Once Germany finally fell, many civilians were raped or killed or starved under the occupying Russian forces. People either hunkered down and hoped for a miracle, or fled to anywhere they could find that was controlled by the French, English, or Americans, who had a reputation for the rule of law.