The rise of the Islamic State (IS) and its rapid conquest of a third of Iraq and Syria are truly astounding. The group’s June 2014 announcement of an Iraqi-Syrian caliphate breaks colonial era borders and its success is unprecedented in the history of modern jihadist movements. Islamic State publications and videos celebrate its termination of the Sykes-Picot accord. With its transnational state, IS achieves a goal that has bedeviled past Islamist insurgencies.Despite formidable adversaries including fellow jihadists, IS has beaten them by resorting to brutal asymmetric and conventional warfare. The Iraqi and Syrian Government have failed to stop them. Opposing jihadists and rebel forces in Syria have persistently lost territory before their rapid advance.