The FBI file also includes information on Zinn’s pro-Castro activism and support for radical groups such as the Students for a Democratic Society (SDS), Progressive Labor Party (PLP), Socialist Workers Party (SWP), and Black Panther Party. Much of the latter was in connection with Zinn’s support for a communist military victory in Vietnam.
Read the rest of that. What is important to note here is that Zinn evidently joined the Kremlin-controlled CPUSA not during the “Popular Front” era of the 1930s — when many idealists were seduced — but after the 1939 Molotov-Ribbentrop Pact in which Stalin cruelly and cynically sacrificed Poland to the Nazis. Zinn was a card-carrying Commie who advocated Marxism-Leninism after the Red Army’s “Iron Curtain” occupation of Eastern Europe, after the treachery of the Rosenbergs and Alger Hiss had been revealed, and even during the height of Stalin’s anti-Semitic “Doctors’ Plot” purge!