This book addresses the issue of defences in international investment law. International investment is the fulcrum around which almost all contemporary business hinges and as the field and practice continue to expand, so too does the law, its practice and the literature on it. For academics who research and teach in the field, and for lawyers who practise international investment law, the material has become massive and, in some cases, unsettling. One such area is the proliferation of forums for settling disputes and the apparent fragmentation of the jurisprudence relating to international economic law. Another is the diminishing parameters of Sovereignty, Act of State and Comity as mechanisms to limit, excuse or avoid jurisdiction or to defend governmental actions. In their place or in addition to those defences, there are now emerging somewhat novel defences such as corruption, bribery, unfair inducement, and mutual culpability. Defences in International Investment Law offers both theoretical and practical insights into investment dispute resolution by delineating and articulating the principles of law that are raised by parties, whether states, businesses or individuals in international investment cases as defence against an action or counter-claim. Providing researchers and practitioners with a comprehensive source for response to claims, Botchway distils and synthesises material from both national and international adjudicatory bodies, international treaties and norms in order to formulate concise principles applicable in defence of actions and counterclaims. Filling a clear gap in the current literature, this book will be of great interest to academics and practitioners of international investment law, investment arbitration and international economic law in general.