Except for Cuba, there is little evidence of much Soviet involvement directly in South American affairs. The US had more or less a free run to do as it pleased. Success or failure might best be judged by the number of friends that the US has in Latin America.

The confrontations have been portrayed as communism against capitalism. Nationalism against imperialism might be more accurate. Personally, I believe racism was a big part of it that is still not faced up to. The former European settlers endeavouring to prevent the indigenous peoples gaining their democratic rights, with American help for the oppressor. "Confessions of an Economic Hit Man" covered this very well.