That would appear obvious to most, but I have heard grumblings around the web from opposition to the war in Iraq who have defended the actions of the insurgents as a justified response to the American occupation. Although I myself did oppose the invasion of Iraq, I fail to see how anyone can rationalize the targeting of civilians, for the acts of the insurgents would seem clearly to me to be indefensible acts of barbarism.
In a 140 page report released last week Human Rights Watch concluded that the insurgent actions in Iraq constitute a violation of humanitarian international law and are indeed war crimes. The detailed report systematically debunks each justification commonly given by the insurgents and also describes who the victims are in this conflict and which groups are responsible for their victimization.
Blogger's Note - Rereading this I can see how someone might come away with the mistaken impression that I'm giving tacit approval of the insurgents actions against US and Iraqi military forces. I am not. The report examined the insurgents actions only from the framework of international law, and as such international law does not prohibit attacks against military targets. However, that does not mean that attacks against the military are not wrong, nor does it mean that it is not a violation of non-international state law.