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

They [ French] still have an open border in Europe. And they have a Europe which doesn't have an integrated intelligence system like we do in the United States.

ISIS, in some cases like Paris, may actually try to direct. But what it's really trying to do is inspire. So its directed activities are these inspired attacks.

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

When you do have really tapped out resources that cover so many investigations, it can help you move through and discard some faster.

I think the vetting we have for refugees is vastly better than the Europeans have.

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.