This reminds me of surgeons who see the answer to a particular illness in terms of their own specialty ... "cut it out". And then there are the internists ... "eat this chemical". And then ... the homeopaths ... "drink this water" ... finally, the faith healers ... "pray to God" (and be cured). It seems that every "expert" interprets data in the light of his own specialty. I'm not a specialist so I have another answer. Just generally speaking ... could it be ... that maybe ...
Civil war ... IS ... the answer?
I have no real use for "diplomacy" which I regard as
Maybe diplomacy could be useful ... if ... one could postpone open conflict for decades until the original litigants were all deceased and their kin could not remember the faux pas that initiated the trouble.
In the case of Iraq, diplomacy appears laughable justaposed with thousands of blown up corpses promoted to that state by the Sunnis. War is the obvious solution here. Let the Kurds and Shiites massacre the Sunnis for a few months till they get the point ... that salvation lies in participation in the non-violent political process wherein they have the little representation they deserve (with respect to their then dwindling numbers). Each day we are visited with the news that some number of suicide bombers have taken out a gaggle of potential police recruits or candy begging kids. Sunnis have the moral dimensions of bubonic rats. War can end this plague ... diplomacy cannot. When philosophies collide only war can resolve the issue. One or the other philosophy is driven into "introspection" and all is well again ... for a time.
As I have noted elsewhere, marshal philosophies (such as that which now possesses the Sunni) are known to respond well to "radiation therapy". Islam in its virulent form can be exorcised by the simple expedient of blowing up Mecca and Medina with two 10-megaton hydrogen bombs. However, in the narrow context of Iraq ... and in view of the fact that only a few tens of thousands of people have been killed by the aforementioned terrorists ... it would be (perhaps) overkill to go at the entirety of Islam. Such a fate should be saved for yet another direct attack on America which I anticipate anon.
An afterthought ...
The complaints brought to bear against the United States for "crimes against Islamic people" pales to insignificance in comparison to the crimes against the Islamic people committed by ... the Islamic people. Just read the papers ... the Islamic papers. Take the tally ... who is really killing whom? Who takes all that oil wealth and squanders it on baubles like those silly Suadi palm frond islands and other such fluff? It is an amazing fact that despite all the wealth given to them by the West in exchange for oil ... the average Arab hasn't got squat to show for it ... not even a quality education ... unless you call Islamic Studies "quality".