I've been very sensitive for a long time to the repeated pattern, during economic hard times or after a war, of the United States' essentially unilaterally disarming.

The reality is, the United States has global interests. Our defense budget is about the same as the defense budgets or military budgets of every other country in the world put together.

No policy has proved more successful in making friends for the United States, during the cold war and since, than educating students from abroad at our colleges and universities.

On the foreign policy side, there's the risk of being too spontaneous and too disruptive where you end up doing more harm than damage. And figuring out that balance is where having strong people around you matters.

One of my favorite little sayings is, 'To avoid criticism, say nothing, do nothing, be nothing.

If possible, to be in a position to announce who is going to step in as the interim immediately. And if possible, to announce who you're going to nominate to replace that person. For that to be somebody of impeccable integrity and reputation disarms a lot of the worst criticism that it's some kind of a power play. It's a professional approach to replacing a senior official, which is always going to get a lot of attention.

I mean, when you get down to very low numbers of nuclear weapons, and you contemplate going to zero, how do you deal with the reality of that technology being available to almost any country that seeks to pursue it? And what conditions do you put in place?