Do tell when this party has ever existed, besides your imagination? Few years during Carter's admin maybe...
Can you name any conflict since (and including) the Mexican–American War that the Democrats opposed? (besides the Civil War of course).
My main point is that I get tired of people from both sides of the aisle democrat/republican making comments about how the other side does or doesn’t do stuff that their own party does as well? It results in virtually no decent discussion and everybody pointing at each other, even though they basically want the same things. It is very cultish and unproductive.
Nixon was actually the anti-war candidate? That didn't quite workout that well but that's what he ran on...
Vietnam mostly started under Kennedy, Johnson massively escalated it and Humphrey still supported continuing it.
Then you had somebody like Eisenhower who wanted who both opposed prolonging Korea and was generally reticent about involving US in the Indochina War (not that he didn't misjudge the situation anyway)