This book outlines the protection standards typically contained in international investment agreements as they are actually applied and interpreted by investment tribunals. It thus provides a basis for analysis, criticism, and stocktaking of the existing system of investment arbitration. It covers all main protection standards, such as expropriation, fair and equitable treatment, full protection and security, the non-discrimination standards of national treatment and MFN, the prohibition of unreasonable and discriminatory measures, umbrella clauses and transfer guarantees. These standards are covered in separate chapters providing an overview of textual variations, explaining the origin of the standards and analysing the main conceptual issues as developed by investment tribunals. Relevant cases with quotations that illustrate how tribunals have relied upon the standards are presented in depth. An extensive bibliography guides the reader to more specific aspects of each investment standard permitting the book's use as a commentary of the main investment protection standards. Describes and explains the protection standards contained in international investment agreements as applied by arbitral tribunals. August Reinisch is a professor of international and European law at the University of Vienna. He is a Member of the International Law Commission, a membre associé of the Institut de droit international and President of the Austrian Branch of the International Law Association. Professor Reinisch has served as arbitrator in investment cases mostly under ICSID and UNCITRAL Rules. He is a Member of the ICSID Panels of Conciliators and of Arbitrators and of the Court of the PCA. Christoph Schreuer was a professor of International Law at Salzburg University, The Johns Hopkins University and the University of Vienna. He has served as arbitrator in investment cases mostly under the ICSID and UNCITRAL Rules. He is a member of the ICSID Panels of Conciliators and of Arbitrators. He is the author of numerous books and articles in the field of international investment law.