The idea that someone can't criticise Stalin because they are perhaps of Jewish extraction is a strange way to go. Stalin was like Hitler a mass murderer of the worst kind. Stalin didn't choose to join the war when he did. The Soviet Union was attacked. They had no choice but to fight. At the start of the war Stalin of course was in cahoots with Hitler carving up Poland between them as well as attacking Finland. I think it is perfectly possible to appreciate the sacrifice of the Soviet people in that war whilst still condemning Stalin for his monstrous crimes.