Most of the people who were responsible for 9/11 are now in custody or have been killed. But there are others, and they plot and they plan, and they hope to pull it off again. And while we have to be right 100 percent of the time, they only have to be right once. So there's no way to overreact to that.

Human beings are not perfect. Their institutions are not perfect, but they have to keep trying. And America has to help people keep trying.

This system, built on free markets, free trade and free peoples and American protection, that's what got us from the end of World War II to the extraordinary events of the end of the Cold War and a system that was one of prosperity and peace for a lot of people, including for the United States.

What we will not wait for is that particular nexus of terrorism, weapons of mass destruction that is extremism, and the technology to come together in a way that is harmful to the United States.

I didn't run for student council president. I don't see myself in any way in elected office. I love policy. I'm not particularly fond of politics.

It takes courage to set priorities because doing so is an admission that American policy cannot be all things to all people - or rather to all interest groups

I'm actually genuinely optimistic about the United States and what's possible in the United States. And when you're out here, you see Americans across racial and economic and socioeconomic lines working together. And you maybe get a little bit less cynical than when you sit in the seat of kind of the epicenter of it all.