capture alive despite the history of isis leadership. a complex task for u.s. commanders here and one that leaves them with they say, substantial intelligence about how isis works and this e detainee. but 19 isis fighters killed in this. some of them said to be foreign and questions being asked as to why the u.s. is willing to endure this substantial risk. a difficult operation to explain to the american public had it gone wrong given the promises barack obama made that he won't put boots on the ground. perhaps we are seeing maybe a higher risk tolerance from the white house in what they are willing to do when going after isis leadership. but it's a stark intervention that was successful in killing a man they hoped to capture. still many questions as to what was entirely in the u.s. cross hairs during this raid. nick paton walsh, cnn, beirut.