Remember the other guy was Japanese. It was two Men one Korean and One Japanese who hated each other but grew into a bond of friendship based on the circumstances that they were in.
Lol what kinda country deserting person would do this...? I think it would be a cool job but how could they honestly trust you to fight for them in the war. You have already been captured twice...sigh
There is a Korean Film called My Way and I highly recommend you watch it. It was on Netflix last time I saw it but it's been a while since I last saw it so who knows if it's still there.
I can't imagine any other way for him to have been recruited by every side without being executed first.