Sean D. Murphy

Sean D. Murphy teaches, writes, and practices in the fields of public international law and U.S. foreign relations law.

Before joining the George Washington University Law School faculty in 1998, Professor Murphy served as legal counselor at the U.S. Embassy in The Hague, arguing several cases before the International Court of Justice and representing the U.S. Government in matters before the International Criminal Tribunal for the former Yugoslavia. He also served as U.S. Agent to the Iran-U.S. Claims Tribunal, arguing cases on behalf of the U.S. Government and providing advice to U.S. nationals appearing before that tribunal. Between 1987 and 1995, he served in the U.S. Department of State’s Office of the Legal Adviser, primarily advising on matters relating to oceans and international environmental law, international claims, and international humanitarian law. Since leaving the U.S. Government, Professor Murphy has represented several countries in international courts and tribunals, including Armenia, Ecuador, Ethiopia, Jordan, Kosovo, North Macedonia, Suriname, Uganda, and the United States, has served as an arbitrator in inter-State and investor-State arbitrations, and has sat as an ad hoc judge on the International Tribunal for the Law of the Sea. In 2024, he was appointed by the U.S. Government to the List of Arbitrators for the World Bank’s International Centre for Settlement of Investment Disputes (ICSID).

Professor Murphy has published numerous articles on international and U.S. foreign relations law. His treatise on The Law of U.S. Foreign Relations (2023) (with Swaine) won the 2024 American Branch of the International Law Association’s Practitioners Book Award and the 2025 American Society of International Law (ASIL)’s Robert E. Dalton Book Prize. His book Humanitarian Intervention: The United Nations in an Evolving World Order won the 1997 ASIL Certificate for Preeminent Contribution to Creative Scholarship, while his article on international environmental liability won the American Journal of International Law (AJIL)’s 1994 Deák Prize for Best Scholarship by a Younger Author. His other books include: Principles of International Law (4th ed. 2025); International Law: Cases and Materials (8th ed. 2025) (with Damrosch & Arato); U.S. Foreign Relations Law: Cases, Materials, and Practice Exercises (6th ed. 2024) (with Swaine and Brunk); International Law relating to Islands (2017); and Litigating War: Arbitration of Civil Injury by the Eritrea-Ethiopia Claims Commission (2013) (with Kidane and Snider).

Professor Murphy was a Member of the U.N. International Law Commission (2012-22), serving as special rapporteur for crimes against humanity. He is currently a U.N. expert for the negotiation of a Convention on Prevention and Punishment of Crimes against Humanity. Professor Murphy is an Adviser for the Restatement (Fourth) on the Foreign Relations Law of the United States and is a Membre Associé of L’Institut de Droit International. Professor Murphy serves on the AJIL Board of Editors and, during 2018-20, served as ASIL President.

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