So you're saying the movie's being political by trying not to be? Thats a no-win argument. I think its pretty clear why the iraqis are portrayed in the manner described, because its a movie from the soldier's POV. Maybe the guy in the beginning of the film who asked Eldridge 'Where are you from?" was just counting coup. Maybe he was a terrorist. Maybe he was just the distraction. We don't know because the soldiers don't know.
Unfortunately, Bigelow is exactly the wrong kind of director to expect any kind of "humanization" story (K-19?) and any such attempt would be a jarring distraction from the film.
But I do get your point about the iraqis. They're just as much of a nonentity to the left when it comes to politics.