The dispute resolution procedures of the World Trade Organization allow sanctions to be imposed when a country is unwilling to bring a WTO-inconsistent trade measure into conformity. Not surprisingly, this form of retaliation often creates as many problems as it solves. This timely work provides in-depth legal analysis of the procedural and substantive aspects of retaliation under the WTO dispute settlement system with particular reference to relevant rules and case law. It examines the retaliation regime under GATT 1947 and the Dispute Settlement Understanding, as well as the special retaliation regime under the Subsidies and Countervailing Measures Agreement. It includes a case study with respect to the calculation of the level of retaliation in Article 22.6/4.11 arbitration. Finally, it explores the gaps in the current retaliation system with regard to both procedural issues and the matter of efficacy, and analyzes all relevant solutions. In sum, this book is designed to examine the way the WTO retaliation system works and explore possible improvements.