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.

Every time we have come to the end of a conflict, somehow we have persuaded ourselves that the nature of mankind and the nature of the world have changed on an enduring basis and so we have dismantle our military and intelligence capabilities. My hope is that as we wind down in Iraq and whatever the level of our commitment in Afghanistan, that we not forget the basic nature of humankind has not changed.

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

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

I consider myself a Republican.

I think it's kind of a stretch. You know, it's one thing if somebody working for the U.S. government has sold secrets to the other side, it's another if they have something in their personal life that they're hiding for which they could be blackmailed. Having evidence that they didn't tell the truth to somebody in the same building where they work, maybe it's just the old intel guy, is - it's a problem.

My last visit to China as secretary, January of 2011, I told President Hu Jintao, just like this, "President of the United States wanted me to tell you that we now consider North Korea a direct threat to the United States." And it had no effect whatsoever.