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.

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.

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'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.

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.

Sovereignty must be redefined if states are to cope with globalisation.