Year of election
Year of titular member


Permanent Observer to the United Nations for the Asian African Legal Consultative Organization

Area(s) of Expertise

Public international law

  • International organizations
  • Settlement of disputes
  • Peacekeeping
  • Multilateral treaties
  • Climate change and sustainable development
  • Human rights law
  • International humanitarian law


  • Permanent Observer to the United Nations for the Asian African Legal Consultative Organization since 2008.
  • Professor, Columbia Law School (1997-2015).
  • Professor, Yale School of Forestry and Environmental Studies (2006-2016).
  • Executive Secretary, UN Conference on the Establishment of the International Criminal Court
  • Secretary, the International Law Commission and the Sixth Committee; Director, Codification Division; Principal Legal Officer, Office of the Legal Counsel, United Nations (1973-2019)


Selected publications

  • Swords Into Plowshares: Building Peace Through the United Nations, Martinus Nijhoff Publishers 2006
  • States’ Responses to Issues Arising from the ICC Statute: Constitutional, Sovereignty, Judicial Cooperation and Criminal Law, 2005, Transnational publisher
  • The International Criminal Court: Elements of Crimes and Rules of Procedure and Evidence, Editor and contributor, Transnational Publications, December 2000
  • The International Criminal Court, The Making of the Rome Statute: Issues, Negotiations and Results, Editor and contributor, Kluwer/UNITAR (1999).
  • Increasing the Effectiveness of the International Court of Justice, Nijhoff/UNITAR (1997), coedited with Cornie Peck
  • New Directions in the Law of the Sea: Global Developments, with Mori Hayashi, Oceana Publications, (1996– -)
  • New Directions in the Law of the Sea: Regional Developments, with Mori Hayashi , Oceana Publications (1995–)
  • Manual on Space Law, 4 volumes, edited with N. Jasentuliana, Oceana Publications (1979)



  • Operational Factors affecting treaty interpretation, Asian Academy of international law and Chinese Society of International law (forthcoming 2017) 1-11pp.
  • An International Normative Framework for Democratization, in Building Democracy from Manilar to Doha: the Evolution of the Movement of New or Restored Democracies, published by Helsinki Process Publication series 2006, pp. 41-132.
  • Making the International Conference on New or Restored Democracies More Effective and Efficient, ICNRD-6, April 2006.
  • Best Practices of Democratization, Mongolia, 5th International Conference on New or Restored Democracies, 2003.
  • The Rwanda Tribunal, in Leiden Journal of International Law, vol.9, No. 1, 1996, pp. 37-61.
  • United Nations Peacekeeping: Development and Prospects in Symposium: Peacekeeping, peacemaking and peacebuilding, the Role of the United Nations in Global Conflict, in Cornell International Law Journal, vol. 28, No. 3, 1995, pp. 619-629.
  • Rule-making in the United Nations:  Opinio Communitatis, in  Journal of International Law and Politics, New York University, vol. 27, No. 3, 1995, pp. 571-576.
  • Legal Developments in the United Nations: The Emergence of inter-organizational Institutions in Asian Yearbook of International Law, vol. 4, 1995, pp. 227-236.
  • The Reach and Relevance of International Law: Legal Framework for Multilateral
  • Action, paper presented at the Annual Meeting of the American Political Science
  • Association, 2 September 1994.  New York in ASIL Bulletin, No. 5, November 1994.
  • Making International Law More Relevant: Dispute Settlement, Legal Advising and Public Awareness : paper presented at the 1994 International Law Weekend to be published in International Practitioners Notebook (special issues) 1994.
  • Administration of Treaties by the United Nations: Why not? in International Practitioners Notebook (special issues) 1995.
  • How Can States Be Enticed to Settle Disputes Peacefully? in Friedenserhaltende und­ schaffende Massnahmen: Die Universale Option (Möglichkeiten, Erfordemisse und Probleme im Rahmen der Vereinten Nationen) (Peacekeeping and peacemaking measures: the universal option (possibilities, necessities and problems of the United Nations) Part C, vol. 6, ed. by W. Kuhne, Ebenhausen, Germany 386 pp. at pp. 269-­292.
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