The first experiment with communism that I'm aware of, was the Paris Commune. It worked great - and scared the sh*t out of the rich and powerful. Nobody was harmed.
Behind the October Revolution and the Bolsheviks - were a bunch of western powers - like Germany (Lenin was sent to Russia by German Intelligence), and Wall Street - Warburg and the Rothschilds and Rockefellers and the Koch brother's father, etc..
Vietnam went pretty well, for the Vietnamese - once the US left them alone.
China brought a Billion people out of poverty. When I was a kid - China was the poorest country on Earth - in the wake of the Japanese occupation, and the Civil War (against US-backed crooks - who became "Taiwan").
Cuba is a MUCH better place to live than Haiti, the DR, or Guatemala or Honduras, etc.. Same with Nicaragua - though they are more socialist, than full-on communist, now.