I understand that feeling and I'm certainly not looking for a fight. But when do we stop being enemies?
Two of our closest allies, Germany and Japan, were our bitter foes 70 years ago. Is Spain still our enemy? The British? Are we still fighting the Barbary pirates? OK, bad example perhaps...
I think much of the animosity, I'm guessing really, comes from the fact that we lost that fight in Vietnam. A political decision was made, in effect, to cut and run.
Besides, I thought the Vietnamese were on our side. Some of them anyway. We welcomed tens of thousands as refugees after Saigon fell.
No, I don't agree that we dishonor our vets by doing business with Vietnam. My beef with Vietnam is the same one I have with China. They are totalitarian systems that maintain power and social control via the threat of violence and imprisonment. I think they have more to answer for in the present than for forty years ago.
I have a 47 year old friend who is still fighting the Civil War.
The British are the only ones you cited where we eventually made peace with the same government we fought against (and it was many decades later).