The self-proclaimed Islamic State is a hybrid jihadist group with a declared goal of establishing a "lasting and expanding" caliphate. Its strategy for survival and growth blends military, political, social, and economic components. Yet the U.S.-led international intervention against it has largely been limited to air strikes. The gaps in the international coalition's approach as well as deep sectarian divisions in Iraq and the shifting strategies of the Syrian regime and its allies are allowing the Islamic State to continue to exist and expand.