As will continue to happen time and time again, these slaughters employed the assistance of Nazis and Nazi adjacents. Most of the people killed were merely Union members fighting for worker protections.
The USA backed technique of utilizing right wingers to coup and slaughter leftists came to be known as The Jakarta Method and is still employed to this day. The recent coup of Bolivia in 2019 was led by a millionaire neo-nazi by the name of Luis Fernando Camacho. Senator Áñez was put into power and immediately gave the military carte blanche to go door to door attacking Bolivian natives and leftists.
When "Tankies" say anti-communism means Fascism, this what they are talking about. The history of Anti-Communism is the slaughter of millions (often indigenous people fighting colonialism) who were simply organizing to not be treated like slaves.
These excerpts are from the book The Jakarta Method by Vincent Bevins
Wrong sub, but the book sounds interesting.