Wrong. Brejnev saw North Vietnam as a spoiler country, to borrow Spengman's phrase, which could ruin his detente with the USA. However, two related factors forced the Soviet Union to help Vietnam. One was the USSR's repeated attempts to become once more the undisputed leader of the international communist movement. The other was its long-running conflict with China. Basically, the Soviet Union was forced to help Vietnam in order to prevent the Chinese from screaming that the USSR was abandoning a fellow communist party in the face of Western imperialist aggression. Well, the Chinese screamed anyway, something the Russians did not like one bit. However, the Soviet Union was also working on the political end by pushing for a meeting of all the communist parties in order to officially rally the movement behind it and against China and its protégé, Vietnam. Given that the failure of North Vietnam's campaign would have meant another US client state on its borders, China was directly interested in USA's defeat. It was China that kept urging the North Vietnamese to fight.Doc wrote:However the Soviet Union was the main ally of North Vietnam during the war and after. Not an ally of the US or an ally of the PRC. That China invaded Vietnam over Vietnam's invasion and removal of Pol Pot in Cambodia(Close Chinese ally) makes that pretty plain. Even if many Americans gave a sigh of relief that Pol Pot was removed.
Ironically enough, it was Romania that repeatedly prevented the meeting from taking place. The conflict between the USSR and the P.R. China was a godsend for Romania because it provided a front for our political guerrilla campaign against the USSR. Both Gheorghiu-Dej and Ceauşescu based their foreign policy on the non-intervention in the internal affairs of other states (neamestecul în treburile interne) and sovereignty, The last thing that Romania wanted was to see the Soviet Union firmly in control of the communist movement and enforcing its ideas about the international division of labor (= economic servitude) through Comecon. As a result, the Soviet Union was unable to abandon Vietnam and to rein in China.
Finally, an interesting bit of history that I came across, a view from the other side, so to speak. In early 1966, the Central Committee of the Polish United Workers' Party sent a letter to the Communist Party of China proposing one of the above mentioned meetings of all communist parties, allegedly in order to explore ways of helping Vietnam. Naturally, nobody was stupid enough to believe the official reasons. Ioan Gheorghe Maurer, Prime Minister of Romania, said during the meeting of the Permanent Presidium of the CC of the Romanian Communist Party that he suspected the Soviet Union of foul play:
"[...] a letter that invites China to a meeting in order to organize the resistance against the USA, drafted in such a way that China and Vietnam would refuse to attend, allows the Soviet Union and other socialist countries to evade, in case of aggression against China, the duties arising from their pledges to support China. This letter could be the start of preparatory action in order to leave China to face the USA alone, in case of aggression."
Alexandru Drăghici, the Minister of Internal Affairs, thought that:
"[...] the current position of the USSR is, in a way, a repetition of the situation around WWII, when they signed the non-aggression pact with Hitler's Germany in order to keep war away from their borders at any price. They actually support the USA position regarding Vietnam, that the Chinese are to blame, not the USA. [...] I agree that we should play a more active role, but please note that our main position regarding sovereignty, independence etc. was made possible only by [the USSR's] trouble with China. It's clear that, absent these failures to reach an agreement, the USSR would have intervened more actively in our internal affairs."