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.

• Features article-by-article commentary on the Resolution, explaining the meaning of the provisions by reference to practice, case law, scholarship and the discussions within the Institute that led to the Resolution
• Brings together all relevant material on the equality principle in a easy to use, logical and intuitive format
• Serves as a first point of reference for all questions on the equality of the parties before international investment tribunals