Hat tip to WoTR for this long article:http://warontherocks.com/2016/01/the-islamic-state-vs-al-qaeda-the-war-within-the-jihadist-movement/?

Taster:
The Islamic State’s rise has reshaped the global jihadist landscape, which for nearly two decades was dominated by al-Qaeda. With the Islamic State seizing the world’s attention, the age of unipolarity within the jihadist movement is over, replaced by intense internal conflict. Each group is firm in the belief that its organizational model is superior to that of its opponent.