This book sets out the nature and the scope of the right to regulate in current international investment law. The book examines bilateral investment treaties and ICSID arbitrations looking at the indicative parameters that are granted weight in practice in expropriation claims delimiting compensable from non-compensable regulation. The book places the potential clash between the right to regulate and international investment law within a theoretical framework which describes the stability-flexibility dilemma currently inherent within international law. Lone Wandahl Mouyal goes on to set out methods which could be employed by both BIT-negotiators and adjudicators of investment disputes, allowing states to exercise their right to regulate while at the same time providing investors with legal certainty. The book serves as a valuable tool, an added perspective, for academics as well as for practitioners dealing with aspects of international investment law.