[Tuna-Fish]

It's questionable how much that really was von Neumann's actual opinion. It was stated during the peak of McCarthyism, and he had a lot of personal contacts with people who had been impacted by it.

Always very vocally being the most anti-communist person in the room might have been just a defensive strategy.

[inglor_cz]

IDK about Hungary, but Czechoslovakia executed almost 200 people for political crimes within a relatively short timespan of true Stalinism (1948-1953). Hundreds more were shot at the border trying to escape, or killed in concentration camps mining and processing uranium ore without any protective gear etc. Thousands survived the camps with health undermined.

Many of those were members of the intelligentsia. An average escapee with an academic title was likely to know at least a few victims by name.

It wasn't hard to hate the perpetrators genuinely.