That's assuming it becomes a stalemate, that ISIS don't capture nuclear material or weapons from Israel or Iran.

I wouldn't assume Iran can defend itself any better from a ISIS on a roll then Singapore could from WWII Japan.

That's the problem for every quagmire created by Western ideals on how to conquer a country there is a steam roller conquer who makes out like Genghis.

What do we do in 15 years if ISIS hold all of the ME? Do we let the next superpower paradigm be a China vs ISIS dominated world?

ISIS are more likely to fold up and fail once they lose momentum. Let Russia support their Syrian strongman and ISIS will be whittled away.

Yes it won't get rid of the root causes, but it isn't allowing an opportunity for something far worse to evolve.