I never thought I'd agree...

...with that notorious neocon John Bolton on anything, but he's spot-on today in his New York Times piece, "To Defeat ISIS, Create a Sunni State" (my emphasis):

Today’s reality is that Iraq and Syria as we have known them are gone. The Islamic State has carved out a new entity from the post-Ottoman Empire settlement, mobilizing Sunni opposition to the regime of President Bashar al-Assad and the Iran-dominated government of Iraq. Also emerging, after years of effort, is a de facto independent Kurdistan.

If, in this context, defeating the Islamic State means restoring to power Mr. Assad in Syria and Iran’s puppets in Iraq, that outcome is neither feasible nor desirable. Rather than striving to recreate the post-World War I map, Washington should recognize the new geopolitics. The best alternative to the Islamic State in northeastern Syria and western Iraq is a new, independent Sunni state.

If it makes you feel any better, Joe Biden was saying things like this years ago.