Also, why aren't the Arab countries doing more to tidy up their own back yard ? Next door to Iraq is Saudi Arabia, a country of almost infinite wealth, and considerable military capability, who seem quite happy to see chaos on their own doorstep ! Maybe even the Iranians should be concerned - after all, IS makes the Tehran regime look like a bunch of pinko Liberals !
Do they imagine that, if IS takes any kind of control of Iraq, that their orders will be "Well, we've conquered Iraq - we'll probably leave it at that then lads !"