Leonard Weinberg is Foundation Professor of Political Science at the University of Nevada. His books include, The Democratic Experience and Political Violence (2001, edited with David Rappaport) and The Emergence of a Euro-American Radical Right (1998, with Jeffrey Kaplan). Ami Pedahzur is an Associate Professor at the department of government, University of Texas, Austin. His latest publications include: Root Causes of Suicide Terrorism (2006), Political Parties and Terrorist Groups (with Leonard Weinberg, 2003) and The Israeli Response to Jewish Extremism and Violence - Defending Democracy (2002). Arie Perliger is adjunct faculty member in the School of Political Sciences, University of Haifa and research fellow at the National Security Studies Center in the University of Haifa, Israel.