Any sign that says we're going to leave Iraq before the job is done simply emboldens terrorists and creates a certain amount of doubt for people, so they won't take the risk necessary to help a civil society evolve in the country.

Reading history while you make history can teach you a lot.

We may discover resources on the moon or Mars that will boggle the imagination, that will test our limits to dream. And the fascination generated by further exploration will inspire our young people to study math, and science, and engineering and create a new generation of innovators and pioneers.

We must have the attitude that every child in America - regardless of where they're raised or how they're born - can learn.

[People] don't judge you on what would have happened in the absence of a decision.

It should make people nervous when non-transparent regimes, that have announced that they've got nuclear warheads, fire missiles. This is not the way you conduct business in the world. This is not the way that peaceful nations conduct their affairs.

I don't worry about long-term history. I won't be around to read it.