>
Of course we could say that at the time it was too hard to see, but Purges had already been going on for long, with millions dead in murders and famines, and people knew. Many just chose not to believe.There was also the fact that they didn't had many legs to stand on.
What Stalin did to its own people, the western powers did the same and worse in their colonial territories. Mass executions, dictatorships, torture, forced labour, police brutality, concentration camps, state-caused famines, and the like.
Just one example: "On the pretext of a slight to their consul, the French invaded Algeria in 1830. Directed by Marshall Bugeaud, who became the first Governor-General of Algeria, the conquest was violent, marked by a "scorched earth" policy designed to reduce the power of the native rulers Dey; this included massacres, mass rapes, and other atrocities. Between 500,000 and 1,000,000, from approximately 3 million Algerians, were killed within the first three decades of the conquest."
It didn't continue any better than that. In fact, until the very 60s, decades after WWII ended, the police beat to death 100 demonstrators, not in some remote backwater, but in Paris itself:
https://en.wikipedia.org/wiki/Paris_massacre_of_1961
And that's just one example from France. There are many other examples from France, Britain, Belgium, and so on.
Besides, they could not care less for the Jews. What they wanted, and fought Germany for, was not to let it rule the world (trade lines, developing nations, crucial territories and so on) -- the same thing WWI, WWII, and the Cold War happened for.
https://www.ushmm.org/wlc/en/article.php?ModuleId=10005267
