It’s easy to say “sunk cost fallacy” but that last bit is very, very tough to get over. Ask any US veteran how they feel about their time in the ME now.

Most of them I know are extremely bitter about being sent over there to begin with, including the very patriotic ones. Very few have an opinion along the lines of "We should have stayed until the job is done". Most express some variant of "We should have gotten out sooner, but also the fact that we left our translators behind to be executed by the Taliban haunts my dreams"

The pool may also be further polluted since saying “yes end the war even if we lose all gains” may be considered an unpatriotic opinion that gets you targeted by Russian police. These are people that can and do jail men, women, and children for such behavior.

That much is true.