But if they're NOT part of any military and they attack our troops, what does that make them?
As stated, most are members of terrorist groups, as shown by their multiple violations of the laws of war.
But it would be possible for a legitimate Iraqi militia to form in opposition to the American occupation, and fight us using IED’s (not much different from mines, really) and suicide bombers, as well as openly. Not that they’d last very long. :)
It’s the target, not the tactics, that makes a terrorist.