Engaging Iran won't guarantee improved U.S.-Iranian relations or a more stable Gulf region. But not engaging means more of the same.

You've got to deploy serious political assets around a plan [in Darfur]. And the George W.] Bush administration has never had a plan. Ever. The Europeans don't want to do anything, saying, "The Americans are in charge of that." And in fact the Americans are in charge of naming it and bringing these resolutions every few weeks to the Security Council.

We know that often holding those who have carried out mass atrocities accountable is at times our best tool to prevent future atrocities.

I think that the only time we will really know what then-President Trump is going to do about the set of challenges that confront him is after he has sat down with his advisers as the commander in chief, when he's looking at the threats and the intelligence from the standpoint of being the number one decider, when he's hearing from his secretary of defense, his chairman, who was the same chairman President Obama had, Chairman Joe Dunford, who is an outstanding public servant, who has led our anti-ISIL effort, on which we're making great progress.

From Richard Holbrooke - and I miss him every day - I learned two things. One, prioritization: Never take your eye off the longer-term reforms. The other thing is, he was a hell of a schmoozer! So I should take advantage of my Irish love of beer and gift of the gab, and build relationships. That's a cherished part of the job, asking someone, "How did you get to be the Rwandan ambassador?" I try to take advantage of the fact that I hope to be here at least until the president's term ends getting to know my colleagues.

I like to think that as I get older I'm getting better at spending time with people who have qualities that make them worth spending time with.

I think the point that we all agree upon is that we have to engage with Russia.