I would agree with that. From our standpoint, the war was never about Vietnam, it was about stopping Soviet progression in Southeast Asia. In the end, that never played out since Vietnam actually had no interest in having a direct Soviet presence within the country, and the Soviets at the time were more focused on Western Europe, not Southeast Asia. One could make the argument that our support of the South Vietnamese was humanitarian in nature. Vietnam was, and to some extent still is, almost two separate countries with respect to the North and the South. The Southern Vietnamese were keenly interested in having our support to prevent the North from taking them over, cutting off their artistic and cultural presence, which is what happened for about a twenty year period until the government opened up the country again. Ironically, however, Ho Chi Minh, who was a southerner, opted to side with the North in the very early years of the conflict as he felt the North was most effective way to oust the French.
Sitting here today, Vietnam has mostly disposed of its government held corporate assets to private investors, and is less socialist than we are. They are also starting to compete with China for industrial exports. Neither Karl Marx nor Bernie Sanders would approve of their implementation of communism.