I think all that changed after World War I, because that was such a traumatic war, with all the brutal inhumane killing. AFter WW I, much of the literature was anti-war and pictured the military as bloodthirsty, heartless fools (to paraphrase Stephen Ambrose). Then THAT changed after the National Socialists invaded the Soviet Union and the sneak-attack on Pearl harbor.
WW II was one of the few wars where there was little to no dissent, because Americans hated the Japs for being buck-toothed sneak-attackers, plus the Nazis invaded the left's hero-nation the Soviet Union so that Liberals and Democrats would do anything to save their favorite country.
I think WW II, Korean, and Vietnam vets were raised as pacifists and look at what they did as something absolutely necessary to do to stop evil, and that it was nothing to brag about.
I don't know what today's vets from iraq and Afghanistan will be like. With improved protection from body-armor, techology, and psychological services, maybe the 21st century warrior will be different.
No hero will ever throw his medals over the White House fence, and then thirty years later stand on national television like a horse faced idiot and say, “Reporting for Duty.”
As a Viet Nam era vet, I found THAT traumatic.