- Nothing is out of bounds for ISIS, including the holiest of Islam's sites during Islam's holiest days, writes Hassan Hassan
- For ISIS, allegiance is what determines a person's chance to live, he says
Hassan Hassan is a resident fellow at the Washington-based Tahrir Institute for Middle East Policy and co-author of 'ISIS: Inside the Army of Terror.' Follow him on Twitter. The opinions expressed in this commentary are solely his.
(CNN)One feature that sets ISIS apart from al Qaeda more than anything else is that they have declared war on fellow Muslims. That is what the group is primarily about, and herein lies the secret to its downfall. Its ideology and appeal can only be discredited by the very people it claims to represent.