The best way to understand today's messy world is to read about the inspiring life and diplomatic genius of Sergio Vieira de Mello. -Walter Isaacson

Before his death in 2003 in Iraq's first major suicide bomb attack, Sergio Vieira de Mello--a humanitarian and peacemaker with the United Nations--placed himself at the center of the most significant geopolitical crises of the last half-century. He cut deals with the murderous Khmer Rouge in Cambodia, forcibly confronted genocidal killers from Rwanda, and used his intellect and charisma to try to tame militant extremists in Lebanon, Afghanistan, and Iraq. Known as a cross between James Bond and Bobby Kennedy, Vieira de Mello managed to save lives in the world's most dangerous places, while also pressing the world's most powerful countries to join him in grappling with such urgent dilemmas as: When should killers be engaged, and when should they be shunned? When is military force justified? How can outsiders play a role in healing broken people and broken places? He did not have the luxury of merely posing these questions; Vieira de Mello had to find answers, apply them, and live with the consequences.

With Chasing the Flame, Pulitzer Prize winner and author of The Education of an Idealist Samantha Power offers a profile in courage and humanity--and an unforgettable meditation on how best to manage the deadly challenges of the twenty-first century.