The Vietnam war, or at least the fighting that us Americans refer to by that name, was started by the sovereign state of North Vietnam invading the sovereign state of South Vietnam and ended when America (and allies) stopped defending the state of South Vietnam and North Vietnam conquered it.
You can make all sorts of arguments as to whether or not it was moral to partition the original state of Vietnam into two separate states or whether it was moral for America to be involved at any point, but I'd make the general argument that the state starting a war with a literal invasion is rarely the moral party in such situations.
You can make all sorts of arguments as to whether or not it was moral to partition the original state of Vietnam into two separate states or whether it was moral for America to be involved at any point, but I'd make the general argument that the state starting a war with a literal invasion is rarely the moral party in such situations.