Well we occupied Korea which was as bad as anything anywhere on earth. As for the Romney boys all getting deferments...perhaps...but likely not all of them. In my opinion the correct answer to all the boys seeking to go on missions was that they could go on missions as soon as they were done with their two years in the infantry (or whatever).
Korea is a peninsula; there was no Ho Chi Minh trail. Also, unlike South Vietnam, Koreans didn’t want communism; as Americans retreated after the Red Chinese entered the war, North Korean civilians followed them south to escape North Korea.