And thus to my final and most melancholy point: a great number of Stalin's enforcers and henchmen in Eastern Europe were Jews. And not just a great number, but a great proportion. The proportion was especially high in the secret police and 'security' departments, where no doubt revenge played its own part, as did the ideological attachment to Communism that was so strong among internationally minded Jews at that period: Jews like David Szmulevski. There were reasonably strong indigenous Communist forces in Czechoslovakia and East Germany, but in Hungary and Poland the Communists were a small minority and knew it, were dependent on the Red Army and aware of the fact, and were disproportionately Jewish and widely detested for that reason. Many of the penal labor camps constructed by the Nazis were later used as holding pens for German deportees by the Communists, and some of those who ran these grim places were Jewish. Nobody from Israel or the diaspora who goes to the East of Europe on a family-history fishing-trip should be unaware of the chance that they will find out both much less and much more than the package-tour had promised them. It's easy to say, with Albert Camus, 'neither victims nor executioners.' But real history is more pitiless even than you had been told it was.
What people still do not like to admit is that there were two crimes in the form of one. Just as the destruction of Jewry was the necessary condition for the rise and expansion of Nazism, so. I first noticed this point when reading an essay by the late Ernest Gellner, who at the end of the war had warned Eastern Europeans that collective punishment of Germans would put them under Stalin's tutelage indefinitely. They would always feel the guilty need for an ally against potential German revenge.
Most German perpetrators were never punished or rewarded for their behavior, but they had learned something about themselves. They know what they did or didn't do in the most morally fraught moment of their lives. They have seen themselves in extreme circumstances and, in that, they have seen their own extremes.