Your Cuban history is a bit muddled. Castro took power in january 1959. He went to the US in April 1959 to make peace and to try to forge a relationship with the USA.

Alas, just as Ho Chi Minh had been rebuffed and rejected, so was Castro.

In both cases (Cuba and Vietnam), the Russians were the SECOND choice of partner, after the Americans.

In both cases, the leaders of a revolution and a nationalist movement thought that Americans would be sympathetic due to their own revolutionary history.

In both cases they were WRONG - the US was on the side of imperialism and corporate interests, not the side of the people and their freedom.

For Americans, "freedom" means the freedom to exploit workers and make as much money as possible without any interference from government, trade unions or other regulatory forces.

And yes, I am a proud "tankie".