I think it was going to be hard to work with Russians on Syria. There is some potential overlap between the U.S. and Russia in that the Russians don't want to see the Syria situation unravel to a point where they have to escalate their own involvement. But at the moment, I don't see the U.S. and Russia on the same page in Syria. Russia seems much more interested in consolidating government control over liberated areas. It seems to me that the U.S. and Russia are proving they can disagree for independent reasons in any number of theaters.

I've worked for four presidents, and I've concluded that almost nothing is inevitable. History is to a significant extent the result of the interaction of personalities and ideas. And so I don't believe war between the U.S. and China is in any way inevitable, and it's well within the province of diplomacy and statecraft to avoid it.

Well, we ought to make clear to everybody that the next Korean War, if one were ever to happen, is going to be the last Korean War because it's going to end with a unified peninsula, and it's go to be under Seoul, not Pyongyang.

You cannot be effective if those who work for you are not. So building their effectiveness ought to be a priority.

I think what Mr. Trump has made clear is that he would not undertake optional wars, what I have called wars of choice, a la, say Iraq in 2003 or Libya, for the purposes of transforming another country. It's not clear whether Hillary Clinton, if she were to have the opportunity, would do such a thing again or whether she would have taken a - the lesson from both Iraq and Libya that we ought not to be undertaking those kinds of wars of choice.

I think Hillary Clinton is more suspicious, clearly tougher on Russian policy in Ukraine, Georgia, Syria; more willing to support sanctions; not against negotiating with Putin, but I would say tougher and more skeptical. And Donald Trump has talked about revisiting policy towards Ukraine, revisiting policy about sanctions towards Russia, not as quick to criticize Putin for what he might be up to in Syria and propping up the regime there - so just seems to be more open to the possibilities of working out some kind of a - I guess you'd call a modus vivendi with Putin.

Donald Trump is much more suspicious of international institutions; much more skeptical of the contributions that America's traditional allies have made; more willing, in some cases, to entertain the possibility of getting along with countries who some would call an adversary, such as Mr. Putin's Russia.