re: Interesting question........
I worked for Gulf Oil at the time, one of the companies in question. There was a big stink about it because a group of conservative stockholders were very upset that Gulf was doing business with a Communist government and Cuban troops were providing security for our assets. The funny thing about it was that the rebels were also Reds, a Maoist gang of hoodlums supported by the South Africans, and reportedly, the CIA. Stranger things than that happened during the cold war.