"There is no justification under international law for the use of military force against Iraq. The UN charter outlaws the use of force with only two exceptions: individual or collective self-defence in response to an armed attack and action authorised by the security council as a collective response to a threat to the peace, breach of the peace or act of aggression. There are currently no grounds for a claim to use such force in self-defence. The doctrine of pre-emptive self-defence against an attack that might arise at some hypothetical future time has no basis in international law. Neither security council resolution 1441 nor any prior resolution authorises the proposed use of force in the present circumstances...

A decision to undertake military action in Iraq without proper security council authorisation will seriously undermine the international rule of law. Of course, even with that authorisation, serious questions would remain. A lawful war is not necessarily a just, prudent or humanitarian war."

• Professor of Law, University College London, 2002-present
  Focus: public international law, the settlement of international disputes, and environmental and natural resources law
• Director of the Centre on International Courts and Tribunals, University College London, 2002-present
• Former Academic Positions: University of London's School of Oriental and African Studies, Kings College London, University of Cambridge, New York University

• Appointed a Queen's Counsel, 2003
• Member of the Centre for Law and the Environment
• Co-founder of FIELD (Foundation for International Environmental Law and Development)
• Mmember of the Advisory Boards, European Journal of International Law and Review of European Community and International Environmental Law

• Lawless World: America and the Making and Breaking of Global Rules, Penguin, 2005
• Documents in International Environmental Law, (co-editor Paolo Galizzi), Cambridge University Press, 2004
• From Nuremberg to The Hague: The Future of International Criminal Justice, (editor), Cambridge University Press, 2003
• Principles of International Environmental Law, Second Edition, Cambridge University Press, 2003
• Justice for Crimes Against Humanity, (co-editor w/ Mark Lattimer), Hart Publishing, 2003
• Bowett's Law of International Institutions, Sweet & Maxwell, (co-author w/ Pierre Klein), 5th edition, 2001
• Environmental Law, The Economy and Sustainable Development, (co-editor w/ Richard Stewart and Richard Revesz), Cambridge University Press, 2000
• The Manual of International Courts and Tribunals, (w/ Shany and Mackenzie), Butterworths, 1999
• The International Court of Justice and Nuclear Weapons, (co-editor w/ Laurence Boisson de Chazournes), Cambridge University Press, 1999
• Principles of International Environmental Law, Manchester University Press, 1995 (Vols. I, II and III); 2nd edition Cambridge University Press, 2003
• Greening International Law, (editor), Earthscan, 1993
• Chernobyl: Law and Communication, Grotius Publications/Cambridge University Press, 1988