Sand is a lecturer in international environmental law at the University of Munich and a former legal adviser for the U.N. Environment Programme and the World Bank. He also serves as co-editor of the journal International Environmental Agreements: Politics, Law, and Economics. His most recent book is The United States and Britain in Diego Garcia: The Future of a Controversial Base. The American Society of International Law published an earlier version of this article, with full bibliographical references, in late August.