One of ISIS' biggest propaganda coups was the beheadings of the aid workers and journalists. Is [Emni], the group that is exporting fighters overseas, also the one that was holding James Foley and John Cantlie and Kayla Mueller?

You have to keep in mind that there's a number of logistical hurdles that they have to jump through in Europe in order to get explosives or guns. So for example, the Villejuif shooter in April 2015 who planned to attack a church: According to French press reports, he was instructed by ISIS to go to a sandwich shop, and the weapons would be waiting for him in a car parked outside. He was just told the make of the car, told to go there, told to pick them up. Putting that kind of attack together, using encrypted communications or other means, is not easy.

If we cover a court case involving a murderer, we would still seek out the side of that murderer, even as we realize that what people say is going to be self-serving.

I'm really curious as to the actual structure of the Emni [the intelligence unit that handles foreign attacks]. And Abu Muhammad al-Adnani, the head of it. There are so few pictures of him. We don't even really know what he looks like. For somebody with this outsized influence projecting murder abroad, you'd think that we would know a lot more by now. And then the role of the hostages.

[People who have left the ISIS] say that there comes a moment when the inconsistencies and apparent hypocrisies of their sheikh lets them down, and they begin rereading scripture and find ways that vouch for a nonliteralist reading of the Koran.

One of ISIS' biggest propaganda coups was the beheadings of the aid workers and journalists. Is [Emni], the group that is exporting fighters overseas, also the one that was holding James Foley and John Cantlie and Kayla Mueller?

They're implementing what was the strategy of Al Qaeda, which was to have attacks of different levels simultaneously. ... So the idea is, on the one hand you have these spectacular attacks that take months to plan, and others like Reda Hame, a French national, who went to Syria and was there for about a week, given a couple of days of target practice and one day of encryption training, sent back and arrested almost immediately.