The U.S. position on Jerusalem was not the reason why there hasn't been progress towards peace. The reason is that both the Israeli government and the Palestinian leadership are divided. And there is an enormous gap between Israelis and Palestinians. To say that this decision is only recognizing reality, that Jerusalem is the actual capital of Israel - well, that's true. But it's a selective recognition of reality.

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 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.

China likes the idea of sovereign rights when it comes to organizing their politics as they see fit, and their economics. But they may grudgingly come to understand certain things differently in the area of climate or disease. China is a country fairly integrated into the world. Yet China is uncomfortable with this idea because they worry it will constrain their freedom, politically and economically, to do what they believe they need to do to maintain political stability and cohesion.

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.

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

Hillary Clinton is pretty much what we would call a foreign-policy realist, someone who thinks the purpose of American foreign policy should be to adjust the foreign policies of other countries, work closely with traditional allies in Europe and Asia towards that end.