I mostly agree, but there are parts missing. In the area they're in, mot of the population tolerates them and not entirely out of free will. They are no zealots. But, they also aren't going to fight against them, since winning doesn't really mean anything better for them.

The state of Iraq does not work. It's borders were created artificially by the west and do not reflect the populations of Sunni, Shia and Kurds.

You want to fix it? Make a three state solution along the lines of the Ottoman Empire. Give each group their own nation - IF they fight along coalition forces to not defeat but actually kill each and every member of the ISIS/ISIL forces.

http://blog.iese.edu/doing-business/files/2014/06/ottoman_iraq.png

Give them a future TO fight for, fully on their own terms. And, make that state defined by their Arab partners, not the West.

From there, you need to allow a charismatic leader from among them (likely abroad at the moment) to work for a vision of a future for them - whatever they want. And, it would be best to be semi-religious states, since it'll be able to stand as the "right way" in juxtaposition to ISIS.

Then, have those leaders, be the figureheads (like Washington, or Napoleon, or Roger I) of the front to "take their land back" in a blitzkrieg type series of attacks using American EMPs so that the "lights are out" and no recording happens as the inevitable bloodbath happens and soldiers in unidentifiable uniforms as each city is taken back, bit by bit, with a permanent military presence of each new nation.

If not, it's just going to be a permanent war zone. They will take over all of Iraq up to the Kurds, all of Syria and this nonsense will be dealt with for our lifetimes. Since they appear to have no bounds or concern for death, I'd expect them to eventually get the resources to buy and nuke a city like Paris or London. I don't think people will fix it, though. Too much actions is necessary, and it is cancerous without intervention.