If your ambition comes at the price of an unbalanced life, that there's nothing else that gives you comfort but success, it's not worth it.

The White House is such an extraordinary, simple, beautiful place. It's an extraordinary piece of our history, because it is the one thing that binds our country together. We don't have a king obviously, but we have this president, and the fact that almost all of them have lived in the same place, and so much history took place in those rooms. You can't help but feel awe-inspired by being there.

When I look at what a writer owes to the reader, it's critical to know that everything you're writing about is not made up in your head. I feel that unless you can document and be certain about what it is that you're writing about, the reader is going to lose faith in your own integrity.

Politicians generally form alliances and not friendships. Individuals and institutions achieve their ends through continual barter. But deals are not bonds. Indeed, intense emotional involvement with anything - with issues, ideology, a woman, even a family - can be a handicap, not only consuming valuable time, but more importantly, reducing flexibility and the capacity for detached calculation needed to take maximum advantage of continually changing circumstances.

What the American Dream means to me is the fact that - what founded this country - when I think about those posters that were put up in Europe, which said, "Come to America and you'll have golden sidewalks. The land will be yours." There was something so inspirational about the fact that these immigrants from all over the world felt that here was a place of freedom, a place of opportunity.

Where's the progress that we're going to see in Afghanistan? You have to keep public support both on the economy and the war or these things will really become troubling.

As a historian, what I trust is my ability to take a mass of information and tell a story shaped around it.