There were no American POW's in Korea until a crazy general disregarded the warning from China and decided to expand the mission and turn victory into an embarrassing truce. The US did all it could to get the POW's back from Korea. Hollywood decided that a pretty young actress and a contingent of stupid actors could end the conflict in Vietnam and of course they made it worse for POW's. Left wingers spit on American Troops coming home from Vietnam and now they pretend to love the Military as long as a fellow radical leftie is in the White House.
Was it not 24 American prisoners that decided not to return to the US at the writing of the Korean truce? I remember a speech by a Major Mayer who had done the research on this problem and it took the name "brainwashing".
Following the Korean War, Col. Phil Corso was on Eisenhower's White House staff. He was in charge of the POW issue. In Senate and House hearings in 1992 and 1996, he explained how Eisenhower made the decision to leave the missing American POWs behind after he, Corso, had explained to Eisenhower that thousands were missing, that US intelligence knew they had been shipped to Russia and China, and that achieving their return would be difficult. U.S. policy was clear, he explained. "We couldn't put pressure on the Soviet Union or the satellites, we couldn't - they had our prisoners and we couldn't put pressure on them. That was it. Our policy forbid us from doing it. If you did it, you were disobeying national policy." In implementing this policy, U.S. executive agencies - State, Intelligence, and Defense - subsequently denied any American POWs were left behind. This is still taking place today.