Laurence Boisson de Chazournes is Professor of international law and Head of the Department of Public International Law and International Organization at the Faculty of Law of the University of Geneva ( Switzerland ). She is also Visiting Professor at the Graduate Institute of International Studies ( Geneva ). Between 1995 and 1999, she was Senior counsel with the Legal Department of the World Bank, with the Environment and International Law Unit. She has appeared before the International Court of Justice and international arbitral tribunals. A consultant and a member of groups of experts with various international organizations, including the World Bank, WHO, UNDP and UNESCO, she is the author of a large number of publications dealing with international law, international organizations and international environmental law and international water law.