I take it you weren't around in the Vietnam era.
Actually, I was.
There was a definite interest in a negotiated settlement to end the war, but North Vietnam and the USSR were pushing the war as part of a larger communist aggression.
The anti war movement in the US in the 1960s was not about a negotiated settlement it was about a Marxist 5th column in the US trying to force an American unilateral withdrawal from South East Asia to allow the Communists to take control.
Which they did in Vietnam, Cambodia and other countries with disastrous consequences. Millions dead in Vietnam and Cambodia and 2 million boat people fleeing Vietnam.
And endless money flowing to the war. At least we don’t have a half million men in Ukraine on Russia’s doorstep, but the cost to us is probably going to be equal to VN.