"From Paper State to Caliphate: The Ideology of the Islamic State" by Cole Bunzel

 "The Islamic State’s harsh strain of Jihadi-Salafi ideology is now more popular today than ever. As long as the Islamic State maintains the trappings of an actual state in Iraq and Syria—or beyond—governing territory and dispensing justice, support for the group and its ideology will continue to grow. While the U.S.-led air campaign beginning in August 2014 has so far arrested the Islamic State’s momentum, it remains unclear whether the campaign will reverse its advance. At all events, political turmoil elsewhere in the Middle East, particularly in Libya and Yemen, is creating conditions conducive to the Islamic State’s intended expansion.
Regardless of the coalition’s long-term success, the military campaign can actually strengthen the Islamic State’s ideology by lending credence to its conspiratorial worldview: namely, the view that the region’s Shi‘a are conspiring with the United States and secular Arab rulers to limit Sunni power in the Middle East. The U.S. pursuit of a nuclear deal with Iran contributes to this perception."  Bunzel 

 http://www.brookings.edu/~/media/research/files/papers/2015/03/ideology-of-islamic-state-bunzel/the-ideology-of-the-islamic-state.pdf