Khrushchev was the head man in the USSR after dear old Uncle Joe. He saw colonies in the Third World being abandoned. It led him to think he could take over by using blacks against Christendom. Marketing Western Guilt, the idea that Europeans owe blacks big time for evermore was was the main thrust. Claiming that Racism is awful played well with blacks. Giving them guns helped them be a nuisance.
The KGB was at the heart of operations. Vasili Mitrokhin, their chief archivist kept notes which surfaced in England. Major Mitrokhin wrote The Mitrokhin Archive with Chris Andrew.
The Mitrokhin Archive II: The KGB and the World tells us that Khrushchev thought that Sputnik proved the USSR was going to beat America at - see page 5. Blacks thought they were going to get rich once they had gotten rid of the colonial oppressors. Ibid 5. Khrushchev threw lotsa money at the blacks, pretty much bankrupting the USSR. Ibid 6. Khrushchev told us nasty colonial oppressors to give back our ill gotten gains to our black victims. Blacks loved it; a major propaganda coup. Further that Racism is awful in the West. Ibid 7 Blacks loved that one. They found out that Russians are even more so later. There is no mention of the fact that they are, always were and always will be racist. The author of The Mitrokhin Archive has swallowed the party line himself.
While Khrushchev had fun at the UN telling blacks to go for it, Eisenhower went golfing. His social secretary was not amused at having to invite 'niggers' [ Andrew's inverted commas, not mine ] to the White House parties. K was annoyed by a Philippino who commented on colonial oppression in Poland etc. Ibid 8
Khrushchev gave his secret speech in January 1961 saying they could use the Third World to win the Cold War against the West. This changed the thrust of Soviet intelligence. It continued under Brezhnev. Ibid 9 - 10. Cuba was a bridgehead in the West. Afghanistan was the tail end of the rear guard in the Soviet fall.