In 1994, AP reporter Samantha Power interviewed Sergio Vieira de Mello, a key player in the UN mission to Yugoslavia, in a Zagreb café. Described by one of Power’s colleagues as “a cross between James Bond and Bobby Kennedy,” Vieira de Mello was even then torn between faith in the UN’s importance and frustration with its limitations. Power and Vieira de Mello would remain friends: Power went on to become one of the leading lights of human rights advocacy, Vieira de Mello headed missions in Rwanda, East Timor, and Iraq. By the time of his death in a Baghdad terrorist attack in 2003, he was one of the UN’s most recognized diplomats. In her new biography, Chasing the Flame: Sergio Vieira de Mello and the Fight to Save the World, Power distills the lessons that Vieira de Mello gathered during his tumultuous career.

Why write about Sergio Vieira de Mello?
Most statesmen have hatched their ideas about diplomacy and humanitarianism from the boardroom, in the capital cities. Sergio did high-level diplomacy, but he also lived among people in broken places. If we’re going to learn from anyone right now, it should be someone with a gritty understanding of how life is lived. Sergio sometimes reacted ingeniously and sometimes he got it wrong, but he was always adapting. Diplomacy in the 21st century is going to look a lot more like Sergio’s life, if it’s done well.

After the Rwanda genocide, the UN was divided about whether to disband Hutu refugee camps that were filled with war criminals; Vieira de Mello described this situation as damned-if-you-do, damned-if-you-don’t. How did he avoid paralysis when confronting so many lousy options?
Sergio’s life runs idealism through the ringer. When you live in Sergio’s shoes, you see that peace and justice can be at odds with each other, or human rights and humanitarianism. In Rwanda, people were saying “You can’t keep these camps open, there are genocidaires in them.” But Sergio said no, there are also millions of civilians, and we have to feed them.

I think of the book in terms of The Education of Henry Adams—it’s the education of a 20th century idealist.

Do you hope that this book will build up more support for the United Nations, both in the U.S. and elsewhere?
For Sergio, the UN was not simply an idea; it was a place to get things done. But the UN you get to know through Sergio’s eyes is even more screwed up than its worst critics would say.

What the UN does is aggregate the selfishness of 192 countries. The UN’s flaws are our flaws—our countries’ flaws, our world’s flaws. How can anyone say with a straight face that the UN is the solution, unless states begin to give up certain things for the good of the commons? It’s not like there’s been a serious effort at reform by countries who really care about the organization. What we’ve had are backhanded, ad hoc conversations between diplomats.

What were the challenges in composing a narrative of Vieira de Mello’s life?
In one way this was the easiest book I’ve ever written. The reporting was a pain in the ass, but it was easy in that I never had to ask twice—Sergio had such a profound effect on people that everyone had strong feelings about him.

Initially the biggest challenge was emotional. I spent the first nine months reporting the last three hours of his life. I found that just emotionally crushing. This guy was a friend, and for all his flaws, that he would have waited under that rubble for three hours waiting rescue from my country and my government, I found that wrenching. Sergio died in a hole.

Could Vieira de Mello have made a difference in Iraq if he had lived?
So many of the decisions that doomed Iraq—to disband the army, to not seek international support, to not secure the borders—were made way before Sergio was involved, and I don’t think the coalition was ready to listen to Sergio when he was there.

In the acknowledgments section of the book, you say that Barack Obama is “the person whose rigor and compassion bear the closest resemblance to Sergio’s that I have ever seen.” How do the two compare? And do you intend for this book to serve as a sort of guide for political leaders like Obama?
With both of them, the ideals are there, they’re part of their being. They share a directed focus on major change. There’s a searching quality to both of them …

When I was working on the book, especially the chapter about the UN in Iraq, Barack would call me with a barrage of questions. He was looking for truth but also for a prescription: to hear mine, not to take mine, to push back and adapt it. He has that same curiosity that Sergio brought to every situation he was in, that same comfort in his skin and across borders—like a chameleon, but not phony.

They both really care. You can’t fake that. Sergio kept in touch with so many people from his field experiences—he paid for his cleaning lady’s kids to go to school; Barack has dozens of people like that. What else can I say? They’re both charming and hot. But please don’t lead with that.