I would say, Big Mick, that the average 18 year old who went to Vietnam, differs quite remarkably from the average 18 year old, who enlists, these days. The average 18 year old, these days is 'much better informed' (and you can interpret 'informed', very freely) and motivated, and has lived with the Iraqi situation since before he knew what one was.

You should know, as well as I do (going by your service experience), that many people join 'the Army' for many reasons.
To generalise about anything (as your GUEST interlocutor has done), is always a bad starting point when formulating an argument, and as I mentioned in a post further up this thread, I can't accept the mindset that carries out these kind of atrocities, as being representative of the vast majority of Armed Forces everywhere.

The average 18 year old now, however, has grown up with a healthy suspicion of all things Middle-Eastern; more acute than that hatred of 'The Yellow Man', and the art of propaganda has developed beyond recognition, since those days.
There are kids nowadays, on both sides of the pond, who, if they wouldn't actually believe that the killing of innocent civilians was right and honourable, they would have no difficulty following orders to do so. The PlayStation generation has been among us for a long while, and whatever people say about the 'NASCAR mentality', you also have to take this mindset on board, as well.
There are also (and always have been), those who sign up purely to 'have a go', 'kick some ass'..., whatever..., and it is my belief that there are more of these kind of people seeking entry into the Armed Forces, these days, than previously. There is a thin line between de-sensitisation, and de-humanisation, and most of these kids have been exposed to it since birth. And some of them seek the army out.

Sociopaths and downright criminals have been joining armies since time immemorial. I don't think anyone could dispute that. We also must never underestimate the 'pack mentality' that we humans possess, no matter where we're from. There are more and more bad apples in the barrel, these days; more, arguably, than there was in the Vietnam days, and there are more that could be easier led into committing atrocities, than there would have been, as well.

Armies are changing, Big Mick. It is slow, but it is getting there. And as much as the 'policy' may to apply the GC in all aspects of operations, even we, the public are getting de-sensitised enough to accept that kind of behaviour; our 'outrage' hasn't affected too much, so far.

In ten years time, we'll not bat an eyelid at it.
Well we might... the youngsters won't.

Jim