Barbara Harff is Professor of Political Science at the US Naval Academy in Annapolis. She has written some 40 theoretical articles, chapters, and monographs. Her recent publications include two books, Ethnic Conflict in World Politics (1994) and Early Warning of Communal Conflict and Genocide: Linking Empirical Research to International Responses (1996), both co-authored with T. R. Gurr. Professor Harff’s current research is concerned with testing sequential models of the causes and accelerators of ethnic warfare and humanitarian disasters. Since 1995 she has been a senior consultant to the White House State Failure Task Force, established to develop empirically-based early warning models of political crises. Recently she took the lead in the Task Force’s analyses of the preconditions and accelerators of genocide and politicide.