they supported the non communist country of south Vietnam
I do not know what goals Vietnam had in Vietnam But the U.S. wanted to keep Vietnam from becoming a communist country.
They tried by upholding a corrupt Government and found that they could not.
To keep the country under control.
China keep China open to U.S. trade.
Menelik II kept control of his country in various ways. He located the royal encampment in Addis Ababa which allowed him to gain control of the kingdom.
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 north Vietnam from taking over south Vietnam....
It weakened support for the war effort and encouraged the North Vietnamese to keep fighting. It created some fissures in US society
When USA invaded Vietnam to keep it from becoming a communist country the people that lived there fought against the USA This made it an impossible for the USA to win. The USA spent many years attempting to subdue the country without success.
escalation. Keep Calm and Carry On, good PLATO friend.
The NVA and ARVN fought in South Vietnam. The only fighting taking place in North Vietnam was between jet aircraft (the air war).