Not being from the US and being born towards the end of the Vietnam war, all I know about it is what I've read. What has always astonished me (from reading) is the (IMO) shameful way that many returning soldiers were treated by their fellow countrymen.
Whether the Vietnam war was morally defensible is a whole other issue - these guys were ordered to fight and they went & did what they were told to do. I know many tried to get out of the draft & some did, but those who went either believed they had to do their duty or didn't have the money to get out of it. Either way, they went halfway around the world to this totally alien country & did what they were told to. Surely any shame for getting involved belongs to the politicians & senior generals etc, not the guy in the jungle?

The war in Iraq also seems to be unpopular amongst certain groups in the US, notably some celebrities, yet the servicemen/women serving there do not seem to be subjected to the same hostility that those serving in Vietnam were. In fact, there seems to be a general heartfelt support for those serving, if not for the reasons that they are there.

I'm curious as to what the difference is. Both wars were/are unpopular in certain sectors of society. Both have been protested against. Both involve, largely, US personnel. In both, there have been reports (whether substantiated or not) of (for want of a better word) atrocities committed by individuals belonging to the US military. Yet, in one, servicemen who had done their duty & gone through unimaginable horrors were shunned when they came home. In the other, the servicemen seem to enjoy hero status.

Can someone please explain it to me?