I don't know what the answer is, we have created an atrocious mess there. Helping Assad restore peace would be a start though.
If we decide to bomb Iraq yet again - this problem will never end. Insanity is doing the same thing over and over and expecting different results.
I don't disagree with you in principle but if the West has the military capability to wipe out IS (as they do) I think they should use it. I don't think we can afford to allow the IS to create a new and permanent state that becomes a hotbed for terrorism on a world wide basis.