Numerous developments across the world in recent years bear witness to States’ increasing skepticism about the benefits of international cooperation and the efficiency of international economic law understood as a multilateral set of rules equally binding on all States. This timely book reviews situations where this new economic nationalism may impact the way arbitration—in both commercial and investment disputes—is practiced. Distinguished international arbitrators and academic experts analyze a wide array of topics, covering a broad spectrum of juristic traditions, geographic areas, foreign investment protection laws, and dispute resolution mechanisms and issues. Topics covered include the following: evolution of the definitions of arbitrable standards; amendments to procedural rules; States’ policy choices as reflected in recent investment treaties; procedural trends to restrict access to investment arbitration; the effects of the Achmea decision in the European Union; growing use of the public policy exception; dispute settlement of public-private partnership agreements; and diversification of dispute resolution methods (e.g., business courts). An important feature of the book is the ability it offers to compare various contemporary transformations of dispute settlement mechanisms, with attention to developments in a number of jurisdictions including the United States, the European Union, China, Canada, Switzerland, Turkey, and the Latin American countries. With its comprehensive analysis of how economic nationalism may lead to limiting the jurisdictional, procedural, and substantive scope of arbitration, the authors underscore the crucial importance of a robust system of international arbitration of economic disputes to ensure a stable and secure world order. The global coverage of the contributions and the insightful views offered in them speak eloquently about their usefulness and outreach for arbitration practitioners and scholars, as well as for professionals involved in drafting policies for economic development or in the negotiation of investment agreements.