I tell young people: If you make a job choice on the basis of something other than your nose or your gut, it's unlikely to work out.... It's perilous to look ahead and be like, "I'd like to be ambassador." I would never have gone to Bosnia or spent years writing about genocide. Do it on the basis of what you can learn.... It's like falling in love. Your whole dating life, you're thinking, On the one hand, on the other hand. Then you meet the right guy, and you're not in list-making mode; you're just with the person you're supposed to be with. Jobs are like that too.

In general, my rule is find out where your heart is, then speak from the heart. People know the difference between that and something scripted.

You could be in the United Nations office all night every night and still feel like you were not making a sufficient dent in the world's problems. I think the key is prioritization. But every job presents the tyranny of the inbox, of allowing the urgent to crowd out the important. So we have to have our lodestars.

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 it came to the Vietnam War, Mr. McNamara was an early advocate of escalation but came to realize the flaws in the American approach earlier than many of his colleagues. Yet in public, he continued to defend the war.

I'm going to Washington on a fateful, even historic, mission. I feel that I am an emissary of all Israel's citizens, even those who do not agree with me, and of the entire Jewish people

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.