Do I believe Edward Snowden contributed to the rise of ISIS? Yes. Would they have gotten there without the help he provided them? Probably. Would they have been able to conduct this attack in Paris without him? Maybe. So the honest answer is I don't know.

Companies made these decisions about encryption when they were finding it very difficult to sell their products overseas because the [Edward] Snowden disclosures created the impression that the U.S. government was inside this hardware and software produced by them. They needed to do something to deal with the perception.

[Vladimir Putin] complimented him. That led Donald Trump to then compliment Vladimir Putin and to defend Vladimir Putin's actions in a number of places around the world.

The [Edward] Snowden disclosures created this perception that people's privacy was being put at significant risk.

One of the lessons we've learned from the last 25 years of terrorism is that groups that have safe havens are able to develop external attack capabilities in a way that groups that don't have safe havens are not. So we need to find a way to squeeze them significantly in their safe haven. Taking away territory that really matters to them is really, really important because it prevents them from focusing on external attacks.

You have to have a military and intelligence approach to removing leadership that results in rapid frequent removals from the battlefield. It's got to be one, two a week, not just one or two every three or four months.

I'm concerned, too, about ISIS' ability, right, to infiltrate people. But we have got some very effective, robust processes for vetting people. We brought in thousands of Iraqi refugees after the Iraq War. Not a single one has ever turned out to be a terrorist because the vetting was so good.