No more than a surgeon can operate while tweeting can you reach your potential with one ear in, one ear out. You actually have to reacquaint yourself with concentration. We all do.

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.

When dictators feel their support slipping among adults, it is not unusual for them to alter school textbooks in the hope of enlisting impressionable youths in their cause.

Countries that intervene militarily rarely do so out of pure altruism.

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.

I happen to miss the Constitution; I thought it was a good document.

There is a convergence of crises that makes it challenging to keep the world's attention.