It is hard to even refer to it as an “insurgency” when the Iraqis are simply fighting to remove foreign troops from their soil. BLM is an insurgency.
The term “insurgency” encompasses such a fight. Of course, the Iraq conflict also included Iraqi Army “bitter enders” and “foreign fighters” eager to fight Americans. Instead of say, going to Ohio to carry out attacks on civilians in the US homeland, the latter went to nearby Baghdad to attack American troops.