The Institute of International Law's Resolution on the Equality of Parties Before International Investment Tribunals
Introduction, Text and Commentaries

The Institute of International Law's 2019 Resolution on the Equality of Parties before International Investment Tribunals represents a major step forward in codification of this essential principle as it applies to investor-state dispute settlement: a principle whose application in this context has attracted increasing controversy in recent years. In this commentary, Campbell McLachlan, who served as the Institute's Rapporteur on the topic, explains the context for the Resolution and sets forth an article-by-article analysis of its provisions, drawing upon a wealth of prior case-law as well as the discussions within the Institute that led to the Resolution. The resulting text is designed to assist counsel and tribunals in investment cases, as well as contribute to the wider debate on the reform of investor-state dispute settlement.

Part I. Application to the Establishment of the Tribunal: 1. Forum; 2. Tribunal Part II. Application to the Procedure of the Tribunal; 1. Parties; 2. Pleading and evidence; 3. Substantive equality of arms.

Campbell McLachlan QC is Professor of Law at Victoria University of Wellington and Arthur Goodhart Visiting Professor of Legal Science Elect in the University of Cambridge. He served as Rapporteur for the Institute of International Law's work on the Equality of Parties before International Investment Tribunals. He is Joint Editor-in-Chief of ICSID Review – Foreign Investment Law Journal and co-author of International Investment Arbitration: Substantive Principles (2nd edn, 2017). He regularly sits as an arbitrator in disputes under the aegis of the Permanent Court of Arbitration and the International Centre for the Settlement of Investment Disputes. He will give the General Course at The Hague Academy of International Law in 2024.