LeeHarveyO said:
We were fighting to stop the spread of communism, and to promote democracy.
The Domino Theory was ultimately proved wrong, since countries like Thailand and Indonesia did not turn communist. Hell, Indonesia took care of its communist party by itself, not requiring outside intervention.
In my belief, from what I've heard, Vietnam could have been more about uniting the nation under one banner, since Ho Chi Min was promised elections held in a united Vietnam after the Battle of Dien Bien Phu, and since they failed to occur, he used military force to do it himself. I don't think that the Western nations should have double-crossed the Viet Min like that, and subsequently started the Second Indochina War.
That said, I found the treatment of the Vietnam veterans disgusting, with the people abusing the soldiers and their government abandoning them. In Australia, the Vietnam War was the first time conscription was introduced in such a large scale, meaning that many young men were unwilling sent to die in Vietnam. Those that came back were labelled 'baby-killer' and the like, with many just following orders (not the massacres, just plain orders). The worst, I believe, was the time it took the Australian government to address the issues caused by Agent Orange, a defoliant that caused many medical problems to the soldiers, with it being only in 1999 or there abouts that the soldiers were given compensation.