He works on international security, human rights and war crimes tribunals. He is the author of Stay the Hand of Vengeance: The Politics of War Crimes Tribunals, as well as articles and book chapters on international justice. He has finished a new book, Freedom's Battle: The Origins of Humanitarian Intervention, to be published by Knopf. Before coming to Princeton, he was a reporter for The Economist. He has also written for The New York Times, The New Yorker, The Washington Post, The Los Angeles Times, The New Republic, and other publications. He has won the Stanley Kelley teaching prize in the politics department.

Ph.D., Harvard University