The question assumes that the Vietnamese people are a singular entity. The process of liberation seems to indicate that this was not the case. However, as Vietnamese society was clearly polarised in this period between a small proportion of the population who supported the RVN and a larger proportion of the population who supported abolishing the RVN and major change to Vietnamese economic and social life, we can consider relations between two groups of the Vietnamese population based on their political alignments and the US forces in Vietnam.
Relationships between US forces and segments of the Vietnamese population could be positive, I am thinking in particular of the urban population produced as a result of the war, the Catholic "comprador" elite, the ethnic Chinese merchant communities, and non-Viet tribal groups in areas of significant US presence.
However, the general relationship between US forces and major segments of the Vietnamese population were hostile. The United States was supplying the significant force supporting first a Catholic dictatorship, and then a series of comprador elite dictatorships. The United States was also responsible for supplying these dictators arms and garnering ancillary support from dependent or neo-colonial allies of the United States. This hostility extended to mass political demonstrations in urban areas aimed at the anti-Buddhist nature of the RVN. It extended to the maintenance of criminal networks who resisted government control. It extended to local revolutionary communes. It extended to support for the Vietnamese Workers Party lead coordination of revolutionary change, logistic support of armed struggle, and direct support of armed struggle. Such a level of "hostility" always needs to be considered in the relationship between US Forces and the Vietnamese population.
This would not normally produce hostility, except that the system the United States supported was fundamentally objectionable to the population, and a significant body of the population developed and politicised the objection. The United States forces supported catholic and rapacious capitalist elites who represented domination, imperial rule and grossly unjust land wage and tax allocation in the villages. The alternative politically represented (at least until 1975), a buddhist compatible moderate movement drawn largely from the population itself who implemented (again until 1975) self-governance, national sentiment and a land justice.
On top of the United States forces representing a reprehensible politics, their practice of occupation developed resentment; as US force often directed itself on the civillian population. In contrast, the violence of the VWP / NFL / PLAF / PAVN / PRG constellation was managed in a way that developed legitimacy for this movement and its local supporters.
There was then an excellence of a kind in the relationship between American soldiers and the majority of the Vietnamese people: an excellence of badness.
- RAND reports on Village politics from the 1960s
- 1960s era criticisms of the impossibility of Malay tactics in Vietnam
- Any basic history of the complex relationship between the VWP and Revolution in the South
- Even Fire on the Lake, as ridiculous as some of its cultural assumptions are, is good on this
- Also the recent spate of papers on VWP strategy post 1954
- Wilfred Burchett's (1964) My visit to the liberated zones of South Vietnam is worthwhile in this regard, you just need to scrape the gold leaf off
- Any decent treatment of the cults or Buddhist urban resistance would pay off here too