a lot of it was about money. >> when the isis guys would argue with the jabhat al nusra men, they'd got's all about money-- it's all about money." like, jabhat al nusra's taking all the cash. and we want, isis want more of that cash. money is the mother's milk of the jihad. everything turns on money. and the moment that the commanders don't have cash to pay the gunmen beneath them, those gunmen are gone within the day. they need falafel to eat. they need gas to put in their trucks. every few hours, the trucks get flat tires. they can't fix the flat tires and move around and shoot people if they don't have cash. (car horns honking) (men exclaiming) >> smith: by mid-2014, baghdadi and jolani were bitter rivals. baghdadi seized the northern syrian city of raqqa from al nusra and then moved to take mosul in iraq. (baghdadi speaking arabic) >> smith: he declared a caliphate, an islamic state encompassing large swaths of iraq and syria. (jolani speaking arabic) >> smith: jolani switched his algiance to bin laden's successor, ayman al zawahiri. at one point, he even harbored some of zawahiri'