As the briefer, my job is to carry CIA`s best information and best analysis to the president of the United States and make sure he understands it.

[Hillary Clinton] never misused [ information that the Central Intelligence Agency has]. She always protected it. I would trust her with the crown jewels of the United States government. And, more importantly, I would trust her with the future security of the country and the future security of my kids.

Donald Trump didn't even understand, right, that [Vladimir] Putin was playing him. So, in Putin's mind, I have no doubt that Putin thinks that he's an unwitting agent of the Russian Federation, although Putin would never say that.

The thing we've learned from the last 20 years of counterterrorism is the significant value you get from removing leadership from the battlefield in degrading the organization.

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.

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.

One great lesson from history we need to keep on re-learning. It is that sometimes your adversaries tell you exactly what they're going to do. How many times did [Osama] bin Laden say prior to 9/11 that he was coming after the U.S.? ISIS made clear that when they established their caliphate in Iraq and Syria, they were coming after the United States too.