Stephen C. Poulson examines some data from Iraq:
Obviously, when “holding” and consolidating control over territory, “insurgent” and “incumbent” groups have different types of violence at their disposal. Nevertheless, in the so-called “Sunni Triangle,” both groups exhibited one particularly similar pattern of violence. Namely, when these competing groups did not control territory they often resorted to more indiscriminate forms of violence. In the case of incumbent forces (the United States and its allies) there was a tendency to use more aerial bombs, which risked killing a greater number of civilians. In the case of insurgents, there was (and continues to be) a tendency to use more land explosives and other types of bombs (e.g. suicide bombs) as they lost control of territory. Insurgents also used more indiscriminate violence when actively fighting against the U.S. army’s offensive campaigns.
The Dish 