The caliphate cracks

WHEN the jihadists of Islamic State (IS) seized Mosul and the Iraqi army fled last June, they became the world’s most dangerous terrorist organisation. Sweeping out of Syria and north-western Iraq, they stormed southward, and came close to taking Baghdad. They murdered male prisoners in gory videos and enslaved female ones. Groups from Nigeria to Libya and Afghanistan pledged allegiance to them. Devotees attacked innocent civilians in Western cities; this week at least 19 people were killed in an assault on tourists in Tunisia (though the culprits are unknown). The IS threat has pushed together unlikely allies: in Iraq America provides the air power while Iran musters the ground forces.

As our briefing explains (see article), IS differs from jihadist groups that have gone before, including its parent, al-Qaeda. It is uniquely brutal in its treatment of foes and uniquely competent as a propagandist. But what most sets it apart is its claim to have restored the Islamic caliphate. The revival of a single state to rule over all Muslims, dating to Islam’s earliest days and abolished in 1924 by modern Turkey after the fall of the Ottoman empire, was meant to eradicate decades of supposed humiliation by outsiders and Arab rulers who presided over the decline of flourishing Arab societies.