===Stalin's tyranny was far from well-known and did not become so until 1956 when his crimes were exposed by Khrushchev at the 20th Congress (after Stalin's death===

.,.,.

Rubbish. The Moscow Trials were well-known at the time: were the subject of Koestler's novel Darkness At Noon, 1940, "set in 1938 during the Stalinist Great Purge and Moscow show trials"(Wikipedia).

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