Paul F. Diehl is Professor of Political Science and University "Distinguished Teacher/Scholar" at the University of Illinois at Urbana-Champaign. He received his Ph.D. in Political Science at the University of Michigan in 1983 and has held faculty positions at the University of Georgia and SUNY-Albany. His recent books include War and Peace in International Rivalry(University of Michigan Press, 2000), A Road Map to War: Territorial Dimensions of International Conflict(Vanderbilt University Press, 1999), The Dynamics of Enduring Rivalries(University of Illinois Press, 1998), International Peacekeeping(Johns Hopkins University Press, 1994), and Territorial Changes and International Conflict (Routledge, 1992). He is the editor of seven other books and the author of more than eighty articles on international security matters. He is the recipient of numerous grants and awards including those from the National Science Foundation, United States Institute of Peace, and the Lilly Foundation. He was the 1998 recipient of the Karl Deutch Award given by the International Studies Association to the leading young scholar on peace and conflict issues. He also received the 1998-1999 LAS Dean's Award for Excellence in Undergraduate Teaching and the 1999 University of Illinois Campus Award for Excellence in Undergraduate Teaching. His areas of expertise include the causes of war, UN peacekeeping, and international law. Nils Petter Gleditsch was trained as a sociologist at the University of Oslo. He is a Research Professor at the International Peace Research Institute, Oslo (PRIO) and edits one of the leading journals in the field, the bi-monthly Journal of Peace Research. He is also Professor of International Relations at the Norwegian University of Science and Technology. He is a member of the Scientific Steering Committee of the Global Environmental Change and Human Security Project and heads the GECHS Project Office in Olso. He is a vice-president of the International Studies Association during 20001-02. He has published widely on the democratic peace, the peace dividend, and environmental conflict.