Contributor(s): Professor Valerie Bunce | Why do publics decide to challenge authoritarian rulers; why do they take different approaches to achieving these ends; and what explains the spread of such challenges across state boundaries? In this lecture, Professor Bunce will compare these three waves of popular challenges to authoritarian rulers providing insights into the MENA dynamic and important issues related to cross-national diffusion. Valerie Bunce is the Aaron Binenkorb Professor of International Studies and Professor of Government at Cornell University. Her research and teaching address comparative democratization, international democracy promotion (primarily by the U.S.); and inter-ethnic cooperation and conflict.