It's amazing how active and skilled the Soviets were at infiltrating local progressive movements, and how ruthless they could be even against other socialists who refused to follow the Moscow program or who insisted on maintaining their independence.

It might surprise you to learn that one of the first things Fidel Castro did when he took power in Cuba was to imprison and eliminate the Russian-controlled Cuban Communist Party, which was in cahoots with the dictator Batista. (They had made a deal to keep the labor unions quiet in return for "favors". The Reds weren't above dealing with right-wing dictators when they thought they could gain some benefit.) It's not that Fidel wasn't Red, he was Marxist from the git-go, it's just that he did not want to lose control of the Revolution. Only when he was firmly in control did he let the Russians back in, on his terms. Fidel also continued the Batista/Communist persecution of the long-established Cuban Anarchist movement, which had a history going back to the Colonial Days.

For a fascinating look at these times, check out:

Cuban Anarchism: The History of a Movement, by Frank Fernandez