In my humble opinion, which might be right or wrong, well in WWII we fought against the Japanese, and to day we help them, sure some are still against us but others as well as another generation learns that in world matters we all need to work together. So it is with Vietnam, it's always that we love the people because they aren't in the arena that leads people into or out of war, our military just fight for country as they are told to do because they are property of the military in the nation they live in While in the war and belonging to a government they have no thoughts of their own and all they do is follow instructions. Recently on Memorial Day you could see soldiers who fought in each war were hugging their adversaries. The fallen comrades probably would think it was a job well done, or a job done the best they could under the conditions. All military alive are proud to have served so I'd think the fallen comrades would also be proud to have served whether or not that country became free or stayed free.
What I've realized over my lifetime is that people in a country ask for help, military comes in and helps them for the purpose that those people could reach their goal, whether their goal is to get someone out of office, or whether it's to be democratic or not. If their goal is reached then the military has done its job.
Sorry I can't read your link.