Mark Boal — American Journalist born on December 29, 1973,

Mark Boal is an American journalist, screenwriter and film producer. Before he became a prominent figure of cinema, Boal worked as a journalist for such publications as Rolling Stone, The Village Voice, Salon and Playboy. Boal's 2004 article "Death and Dishonor" was adapted for the film In the Valley of Elah, which Boal also co-wrote... (wikipedia)

One big, glaring difference I can think of between Iraq and Vietnam is the news coverage. During the Vietnam War era, you had TV coverage of the war saturating the airwaves every night, and that coverage wasn't put through a military filter at all.
I mean, journalism is very detailed... you try to get down in the weeds and sort out exactly what happened. And I don't think that a feature film is really a place where that happens.
I actually think every war movie is an antiwar movie in its own way - with the exception of some of the propaganda movies.
Passage of time can be mind-numbing to figure out in a screenplay. It's the easiest thing to do in prose, not just by writing 'four years later', but you can shift time in a sentence or two.
9/11, the wars and terrorism have affected all of us in different ways: people who lost family on 9/11, the people who lost family in the wars and people who lost family in various terrorist attacks that have occurred since.