OK, suppose an expeditionary force is assembled and landed in Arabia. Further suppose they kill people and break things to the point that ISIS says, “we give up”.
What then? How is Arabia to be governed, and by whom?
Arabia? ISIS conquered Arabia?
Perhaps imperialism is the answer. The British have experience in that regard. Let his Lordship have a go at it.
Argentine them in an area with shoot on sight orders for any violating it. Forever. What they do inside the zone is on them.