I will always be an advocate in terms of wars of necessity. I am just much more cautious on wars of choice.

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.

I think Donald Trump has gotten China's attention to a degree that his predecessors have not that this is a very serious matter for the United States.

No president is well-served by groupthink or by everybody singing from the same sheet of music they think he's on.

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.

You know, if I were an - if I were a Taliban, I'd say, 'What did al-Qaida ever do for me except get me kicked out of Afghanistan?'

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.