Campbell McLachlan

Prof Campbell McLachlan profile picture

Professor Faculty of Law


QC, LLB(Hons) Well, PhD Lond, Dip (cl) Hag Acad Int'l Law

Research Interests

Public International Law, Private International Law, International Arbitration


Professor McLachlan completed his undergraduate degree at Victoria University of Wellington before postgraduate studies at University College London and at The Hague Academy of International Law. He practised law as a partner in Herbert Smith London, where he headed its International Law practice group. Returning to a Chair in Law at Victoria University of Wellington in 2003, he has taught and researched in Public and Private International Law and International Arbitration and Dispute Resolution.

His principal books are International Investment Arbitration: Substantive Principles (Oxford UP, 2007, 2nd edn 2017) and Foreign Relations Law (Cambridge UP, 2014). He is a Specialist Editor of Dicey Morris and Collins on the Conflict of Laws (15th edn, 2012) and co-editor of ICSID Review–Foreign Investment Law Journal.

He was the first New Zealander to be invited to give a special course at The Hague Academy of International Law (Lis Pendens in International Litigation Nijhoff, 2008).

Professor McLachlan has served as President of the Australian & New Zealand Society of International Law. He was elected to American Law Institute in 2005, where he was appointed an international advisor to the Restatement Fourth Foreign Relations Law. He was elected to the Institut de Droit International in 2015, where he served as the Rapporteur of its 18th Commission on ‘Equality of the Parties before International Investment Tribunals,’ whose work resulted in the adoption by the Institut of a resolution in August 2019.

Professor McLachlan has held visiting fellowships at the Lauterpacht Research Centre in Cambridge, All Souls College Oxford and at NYU Law School. In 2019 he is a Senior Research Fellow in the Berlin-Potsdam KFG Research Group ‘International rule of law: rise or decline?’ where he is working on a new book on Systemic Integration in International Law. In 2020, he will hold the Arthur Goodhart Visiting Professorship of Legal Science in the University of Cambridge.  He has been invited to give the General Course at The Hague Academy of International Law in 2024.

Professor McLachlan also practises law. He was made Queen’s Counsel in 2007 and is an Associate Member of Bankside Chambers (Auckland & Singapore) and Essex Court Chambers (London). The New Zealand Government has nominated him to the List of Arbitrators of the International Centre for the Settlement of Investment Disputes (ICSID). He serves as president or arbitrator in cases involving sovereign states under the aegis of ICSID and the Permanent Court of Arbitration (PCA).

Recent publications

‘The assault on international adjudication and the limits of withdrawal’ (2019) 68 ICLQ 499.

‘Five conceptions of the function of foreign relations law’ in C Bradley (ed) The Oxford Handbook of Comparative Foreign Relations Law (Oxford UP, 2019) Ch 2.

‘Equality of Parties before International Investment Tribunals’ Institute of International Law, Session of The Hague, Yearbook of the Institute of International Law, Preparatory Works (2018) vol 79 (Pedone, 2019).

The Dynamic Evolution of International Law (ed) Symposium Issue (2018) 49 No 4 VUWLR.

‘The foreign relations power in the Supreme Court’ (2018) 134 LQR 380.

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