It is important for us to understand that the way we are perceived in the world is going to make a difference, in terms of our capacity to get cooperation and root out terrorism. And one of the things that I intend to do as president is to restore America's standing in the world.

What is certainly true is that the American people, just like the German people, just like the British and people around the world, are seeing extraordinarily rapid change. The world is shrinking, the economies have become much more integrated and demographics are shifting.

Those of us in positions of responsibility, we'll need to be less concerned with the judgment of special interests and well-connected donors, and more concerned with the judgment of posterity.

Those who are troubled by our existing programs are not interested in a repeat of 9/11, and those who defend these programs are not dismissive of civil liberties. The challenge is getting the details right, and that's not simple.

Islam has always been part of America

There is a wonderful book called "Gandhi's Truth," by Erik Erikson, the psychologist. It is a great book. And I remember reading that and thinking about this connection between what we think in our personal lives and how that manifests itself in our politics. Those are two books, just off the top, that I think are sort of representative of reading that I did at that time. I never get a chance to read anymore.

ISIS is not an organization that can destroy the United States. This is not a huge industrial power that can pose great risks to us, institutionally or in a systematic way. But they can hurt us. And they can hurt our people and our families.