John,
you are unusual. You know, my father in law was also in Vietnam, as a airforce pilot. But his attitude is very different. He holds grudge - maybe not against Vietnamese, because he did not have too much personal interactions, but against all these liberals and communists... here in the USA.
It is very courageous from you to say that you do not believe that Vietnam war made too much sense, yet - to be a part of it.
My mother was always on the American site - in spite of our mass media which were so much against it. Officially we were always supporting the partizans.
I guess, the truth is somewhere between both sites. As I said before, at least Vietnam war was purely ideological.