What does communism mean? Ho Chi Minh had been a great admirer of the United States and indeed was influenced by the declaration of independence.
The North Vietnamese essentially saw the war as a civil war of unification rather than an ideological struggle. Forms of socialism were popular in many third world countries as a response to colonialism derived handicaps. However, the notion and reality of communism as a powerful monolithic entity was already in decline. Yugoslavia had broken away successfully, Hungary had had its failed uprising, cracks were showing with China.
The Vietnamese loathed the Chinese and vice versa. Russia was too far away to exercise power directly.
Truth is that a unified Vietnam under Ho would be up for grabs. With a little flexibility and a little astute bargaining Vietnam could have entered the American orbit of influence, downplayed its socialism slightly and everyone would have been happy.
Without the steady expansion of the war into Cambodia, secret bombing and CIA Coups, the Cambodian government would have remained functional and the Khmer Rouge would have remained weak flakes. Laos would have continued to be an obscure inland buffer state between Thailand, China and Vietnam that no one would have cared much about.
Meanwhile, America could probably have afforded the great society, if it wasn't paying for a ruinous war. Without the impetus to a runaway military industrial complex that the Vietnam war pushed, more of America's consumer manufacturing economy might have remained viable, and America might still be an industrial power today, rather than a colossal ponzi scheme.