My dad served in Korea. He said very little to me about his experience there. But one thing he did say was that one of his big fears he and his friends had was being captured and being taken to the Soviet Union. He more or less said that it was known that some captured Americans were taken by train into the Soviet Union and never seen again.
Or maybe they do come back - but "different."

Regards,
kid i used to pal around had an uncle who never came out of korea. pics of him as a pow surfaced periodically until the late 70s. roger dumas was his name. nephew was greg.