Therefore if you include mechanics relating only to the injustices committed in democratic countries you run the risk of modelling a rather absurd world where only the democratic nations are shown to be internally repressive, which seems somewhat twisted.
Well, there is the Great Purge. And even if you don't include that-which-shall-not-be-named, even something like hunting for Anti-Nazi resistance in Germany like communists or members of the military could be a way to reflect internal strife.