We're not going to have a perfect batting average and it's important that Americans understand that.

We can't be French and Muslim at the same time. And that's exactly what ISIS wants that population to think.

I don't think bulk data collection was an enormous factor here, because generally, that deals with overseas calls to the United States. But what bulk data collection did was make the process more efficient. So there were no silver bullets there.

I think we have started accelerating over the past years. It's a modernization of NATO. It's at air, it's at sea, it's undersea, it's in cyber. Estonia in 2007, hit by Russian cyber-attacks. So what you see there with those exercises are critical.

We need additional funding for more U.S. combat brigades in Europe. NATO needs to continue to modernize. It is starting to show with the Russians but these exercises are central to show that the alliance is firm, especially as the E.U. starts to have some weakness on the economic front.

We have a Muslim population which is better off economically, better engaged, and less drawn to the fight in ISIS. But as we've seen in places like California and elsewhere, we still have a threat, even if smaller.

You have the intelligence front and the engagement front. On the intelligence front, the French are better than many of their European counterparts. But they are really challenged in two specific ways.