The USA is guilty of committing many terrible war crimes in its efforts to win this war, but in the end they lost the war. The Vietnamese communists 'won' the war, but thirty years later Vietnam was fast changing to a capitalist system. The Vietnamese people are still living under a regime that allows limited personal freedom – this is nothing new, both sides of the Vietnamese conflict at the time Australia became involved were oppressive.
Four million were killed during that war, 7000 have been killed since the war, and in 2008 ten people were still being injured each month by left over mines and cluster bombs in Quang Tri province alone. The damage to Vietnam's people and environment was horrendous. What did the war achieve for either side?
One might have hoped that the USA and Australia would have learned from the Vietnam war that war can be futile. Even this did not happen. The governments of both countries, together with the United Kingdom, stupidly started an equally futile and unethical war in Iraq in 2003.
Also see Killing in peace and war.
More can be read on the futility of war at Rense.com.