I remember being fed the "Domino Theory" growing up near the beginning of Viet Nam. Since I'm too young to have lived during Korea, I wonder if that was the same thread of thought. Korea falls, then China moves into the Pacific (Hawaii.....) and on to the mainland.
I did have an uncle or two who served during Korea. I'm not sure where, might have in the Navy. I did have a cousin killed in Viet Nam. He was a truck driver carrying helicopter fuel. The story I heard was when he died he filling in for someone who was too wasted to do his job that day.