"Both Lenin and Stalin killed millions or workers and peasants, their left-wing ideological opponents, and even members of the Bolshevik party. This bloody and treacherous history is why them is so much rivalry and hostility between Marxist-Leninist and Trotskyite parties today, and it is why the “workers’ states,” whether in Cuba, China, Vietnam, or Korea are such oppressive bureaucracies over their people."
January 1, 1970
https://en.wikiquote.org/wiki/Joseph_Stalin