It is? When was South Korea under commercial embargo? I agree that the piece is extremely biased, but it's pretty clear that the US were about as keen on helping post-war Vietnam developing its economy as they have been with Cuba.
First google hit.
As far as invaders go, both sides invited so many vistors and advisors its hard to say who that is.
As you can see, most of these divisions were short-lived and that idea that Vietnam was one unified country for a long period of time before being arbitrarily split by warring politicians is not correct.
Framing the Vietnam war as a communist struggle against Western invaders is naive and incorrect. South Vietnam was governed by a nationalist but anti-communist government that sought aid from the US and others, while North Vietnam was a communist government that was aided by the USSR and China.
It's well on it's way to becoming South Korea.