I had an eye-opening experience in Baghdad at the end of 2004 and I thought that the story of these guys who have one of the most dangerous jobs in the world would be an interesting way to look at the war in a broader sense.

Ever since 9/11, I found myself interested in chronicling the war and the war on terror and the way that this giant machinery was affecting individuals.

I write on a computer, on a laptop or whatever.

The fact is that war films, by their very nature, are pitched at a high dramatic range.

For better or worse, most of my writing life has been about people that work behind the scenes. I'm interested in finding extraordinary moments in otherwise normal people.

For weeks after 9/11 you could smell the dust and pulverised concrete in New York, and the National Guard came in, so there was a military presence on the streets. It was intense. Overwhelming. Heartbreaking.

I actually think every war movie is an antiwar movie in its own way - with the exception of some of the propaganda movies.