I've spent my entire adult life with the United States as a superpower and one that had no compunction about spending what it took to sustain that position. And it didn't have to look over its shoulder because our economy was so strong.

Well, Israel, obviously, thinks of the Iranian nuclear program as an existential threat to Israel.

I think in the context of senior government positions, I think an anecdote of what I told President-Elect Barack Obama when we had our first meeting. And I said, "You don't know me. Can you trust me? Why do you think you can trust me?" and so on. But at the end, I said, "You can count on me to be loyal to you. I will not leak. I will keep my disagreements with you private. And if I cannot be loyal, I'll leave." Loyalty means doing what you think is in the best interest of that person as well as the country.

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

There is no international problem that can be addressed or solved without the engagement and leadership of the United States and everybody in the world knows that, its just fact of life. So sometimes I think we could conduct ourselves with a little more humility.

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.

What I know concerns me. What I don't know concerns me even more. What people aren't telling me worries me the most.