Introduction
This post addresses issues being considered in the UNCITRAL Working Group III process in relation to the design of a multilateral instrument on investor–State dispute settlement (ISDS) reform (hereinafter an ‘MIIR’). An MIIR is envisioned as the legal mechanism for applying the various reform options being developed by UNCITRAL Working Group III to the extensive network of existing investment treaties. A first draft of an MIIR was published by the UNCITRAL secretariat in July 2024 (A/CN.9/WG.III/WP.246) and this was discussed by Working Group III in the first part of its Fifty-First session in February 2025 (A/CN.9/1196 paras 31–94) and in its Forty-Ninth session in September 2024 (A/CN.9/1194 paras 105–121). Ahead of the Working Group’s February 2025 session, some participants also made written submissions on the topic of an MIIR, including the European Union (EU) and the United States.