The Investor-State Dispute Settlement System is a thought-provoking and important contribution to the ongoing worldwide discussions and debates regarding the way forward for investor-State dispute resolution. The investor-State dispute settlement (ISDS) system provides a mechanism, based on international arbitration, to resolve disputes between foreign investors and States. The number of ISDS arbitrations has increased significantly over the past decade. Drawing contributors from around the world, the authors provide insights into critical topics regarding possible ISDS reforms, their feasibility and alternatives. This book analyses and considers various proposals and reforms under consideration by UNCITRAL’s Working Group III. It provides insights into how several geographic regions and economic cooperation areas have sought to address the question of reform of the ISDS system, including the European Union, the Middle East, and the new United States-Mexico-Canada Agreement. By providing a balanced approach with its much-needed and informed analysis of investor and State rights and duties, this book will be welcomed by all who practise in the ISDS field, including arbitrators, counsel, State governments and non-governmental organizations, regional economic organizations, and international investors. As a guide for parties to the key areas of conflict and concern with the present ISDS system, it will be a readily accessible book that will have relevance for years to come.