The importance of strengthening Euro-Atlantic security: the growing dangers pile pressure on our rules-based international system, so we need to do more to strengthen NATO, the bedrock of our defense - not just upping spending, but making the alliance more agile and more capable of tackling dangers from all directions.

We face now an era where we're going to be fighting the terrorist threat. I mean, that's simply a reality we are going to have to address that one.

Find the enemy that wants to end this experiment (in American democracy) and kill every one of them until they're so sick of the killing that they leave us and our freedoms intact.

There is nothing better than getting shot at and missed. It's really great.

The first time you blow someone away is not an insignificant event.

ISIS is a threat to all civilized nations. America's intention is that the foreign fighters do not survive the fight to return home to North Africa, to Europe, to America, to Asia, to Africa. We're not going to allow them to do so. We're going to stop them there and take apart the caliphate.

The destruction that we have wreaked in the various theaters in which we've been engaged is really quite astonishing. But again, lethality, destruction, killing doesn't seem to achieve our objectives. So, my own sense is that a lack of lethality does not define the core problem.