Lopez is professor and Rev. Theodore M. Hesburgh Chair in Peace Studies at the Kroc Institute for International Peace Studies at the University of Notre Dame. Currently a Jennings Randolph Senior Fellow at the United States Institute of Peace, he is widely regarded as the foremost expert on sanctions. His research focuses on the problems of state violence and coercion, especially economic sanctions, human rights violations, and the ethics and use of force. From 1998 to 2003 he served as chair of the Bulletin's board of directors.