Some people have said, in so many words, that I'm kind of wooly-headed in believing that the Iranians would see not having nuclear weapons as more in their security interest than not.

It has become clear that America's civilian institutions of diplomacy and development have been chronically undermanned and underfunded for far too long - relative to what we spend on the military, and more important, relative to the responsibilities and challenges our nation has around the world.

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

I fired a lot of senior people myself and I think the key, when you feel compelled to remove a senior official, is essentially to have all your ducks in a row at the beginning. Have everybody understand what the rationale was.

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.

I had no difficulty as Secretary of Defense moving from the Bush administration to the Obama administration.

I think that Vladimir Putin has decided, in a very strategic way, to turn the tables and do everything in his power to, as we've described Russian elections as illegitimate, to try and communicate to the rest of the world that Western elections are illegitimate. And it's not just us, we know that now. It's Germany, it's France, it's a number of other countries.