Inside ISIS philosophy, Will McCants on the inscrutable enemy

"His nickname in the neighbourhood was 'The Believer,' because of his extreme religiosity, and also his penchant for telling off family members and friends."- Will McCants describing Al Baghdadi as a young man

Inside the Nuri Mosque, in Mosul, Iraq in June of last year, the shadowy leader of a shadowy group known as ISIS made an ominous declaration. Abu Bakr al Baghdadi rose to declare the re-emergence of the Caliphate... or Islamic State. 

And though his militant group had seemingly arisen without warning over the past year or so out of the swirling chaos of Syria and Iraq, its rise from that moment has been virtually unstoppable.

The Islamic State controls huge swathes of land and people across the region... and routinely stuns the world with its brazen attacks on hostages... shared through slick video productions.

And as investigators in Egypt comb through the wreckage of last month's explosion of a Russian passenger jet, many fear the hand of ISIS will ultimately be found to blame.

For all its impact, ISIS and the man who leads it remain inscrutable, though Will McCants is shedding some light with his new book, "The ISIS Apocalypse: The history, strategy, and Doomsday Vision of the Islamic State." 

Will McCants is director of the Brookings Institution's Project on U.S. Relations with the Islamic World in Washington, D.C. 
 

This segment was produced by The Current's Naheed Mustafa.