Shockingly enough, what people say during campaigns is meant to increase the odds they get elected.

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.

Some governments are prepared to give up elements of sovereignty to address the threat of global climate change.

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.

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.

We ought to be doing much more in North America. We are on the cusp of an energy revolution. And we do need to be doing more at home. The biggest national security threats facing the United States right now are not in the Middle East. They are domestic.

If there's any country that has the capacity not to control North Korea, but to influence North Korea, it's still China. The Chinese always say they have very little influence. They have more than they say they do. We should put pressure on them to do it and there's finally, we're seeing the first signs of a little bit of Chinese disaffection. At some point they're getting tired of the antics of this country. This is a dangerous ally for China to have. And the more Chinese can pressure them and put the economic screws on them, the better it will be for everybody.