I’ve only watched the first 18 minutes of this but it is a very interesting perspective on ISIS and the other terrorist groups from a former Al Qaeda fighter who considers himself an Islamic scholar. From what I got so far is 1) ISIS and the terrorist groups are deluded Muslims who wrongly believe they should fight against other Muslims because of differences in interpretation – the calls them ‘takfiris’. 2) ISIS started in Iraq and was smuggled into Syria and are now returning. 3) ISIS and similar groups were funded and trained by the Americans, Saudis and Gulf States 4) ISIS owe their studied savagery to the model of Ghengis Khan not that of the Prophet.
There is a transcript here.