Did any US soldier defect to the Viet 'Cong' (or NVA?)

Factual Questions
1

I know two did in Korea, it was on 60 minutes.

But any G.I. go “Ho Chi Minh” on us? Surely with so many hundreds of thousands, there was one ‘Hanoi John’ among them?

2

I vaguely remember reading that it happened. Google seems to back that up.

3

There were 21 in Korea, but just 2 in Vietnam, apparently: