A lot of leftists really seem to hate Khrushchev, it's like everyone points at him and says "and this is where it all went down hill". If you're a Khrushchev-stan in the comments show yourself because more than likely there isn't one. Lenin's the goat, Stalin's a problematic fav, but Khrushchev leaves the bland taste of cardboard in my mouth. The thing is, IDK who would really have been better? Zhukov might have been a good general but I can't say he would have been a good governor, like I said IDK. Please enlighten me oh wise hexbear with your years of theory under your girthy communism enjoyer belts.
That was just Realpolitik, though. Khrushchev wasn't backing Cuba because he was a huge fan of Che and Fidel. He was backing Cuba because Eisenhower had just moved Jupiter Missiles into Turkey and this was the tit-for-tat counter-move. Similarly, control of the Suez Canal was incredibly important for trafficking out of the Black Sea. Support for Egypt was paramount to Soviet international trade relations.
Vietnam was, similarly, a central player in Pacific sea trade for the Soviets, following the Sino-Soviet split. Incidentally, I'd argue that set the entire Communist project back a solid 50 years. A united Russia/China might have produced the kind of sustained economic development that dwarfed the West inside another generation. But they fumbled the bag.