I do not know that much about the Cold War in regards to the Middle East, but most Marxists of whatever variety hold very positive opinions on Nasserism, Pan-Arabism during the Cold War or even Ba'athism. While Nasser didn't align too closely with the Soviet Union, whether due to ideological disagreements or simple pragmatism / necessity, he was still a socialist, even if not a Marxist one.

So I have been wondering in particular since a lot of communists see Nasser and other pan-arabian or "arab-socialist" leaders like Gaddafi positively, why did the North and South Yemen split remain throughout the cold war? As far as I'm aware South Yemen was at least nominally a marxist-leninist state while North Yemen initially was a monarchy, but was then overthrowing by a pan-arabist pro-Nasser movement, ending up socialist in some way. Was there not enough common ground found for Arab communists to fully integrate themselves within Nasser's pan-arabism?

Likewise Syria "left" the United Arab Republic following a coup by disgruntled Syrian military leaders, but interestingly enough the communist party of Syria seems to have supported this coup and secession from the UAR. I cannot find much on the reason however. Could someone explain this?