Isolationists made little effort in the early (Post Dien Bin Phu) days. It was the anti war protests against the war and the draft that fought against the Vietnam War.
To keep America out of the war in Europe and Asia.
isolationists
National security matters are authorized to be classified.
The isolationists wanted to keep the US out of the war meaning they would have to be isolated. Being neutral means the US stayed out of war and no getting involved. Which explains why an Isolanist would want the neutrality act to be passed.
They tried by upholding a corrupt Government and found that they could not.
The Korean war
To try and keep South Vietnam from falling to the Communists, and because the government of South Vietnam was too corrupt and incompetent to defend themselves. The government of South Vietnam was never able to defend themselves, and President Gerald R. Ford finally gave up on them in 1975. They soon fell to communist North Vietnam.
The common link was a Communist government. It was in China's best interest to keep North Vietnam as an ally which also allowed the opportunity to spread Communism.
I do not know what goals Vietnam had in Vietnam But the U.S. wanted to keep Vietnam from becoming a communist country.
to keep north Vietnam from taking over south Vietnam....
To keep Vietnam from going nuclear. Vietnam was part of the cold war.
The US objective was to bolster the government of South Vietnam and keep it from being taken over by North Vietnam. The US spent much money and human life trying to achieve this goal, but in 1975 South Vietnam collapsed under a North Vietnamese invasion.