This book brings together all essential documents, materials, and case law on international investment law and international investment arbitration. These extracts from the primary material are accompanied by explanatory commentary placing the documents in their wider context within the international investment legal system. International investment law has emerged as a dynamic area of international law, ripe with controversies over the balance between state sovereignty and investment protection, the decentralized system of international investment law, the scope of international investment agreement protections, investor-state arbitration, and the rights and obligations of international investors. This book highlights each of these controversies, providing an overview of the historical development of international investment law, its purpose, its contractual protection, and the background to investment treaties. It assesses the substantive obligations required by the applicable law and the key issues currently facing the field, including umbrella clauses, exceptions and defences, and reparations. The book gives a detailed overview of international dispute settlement, introducing the fundamental features of investor-state arbitrations, before demonstrating the significant jurisdictional hurdles a claimant faces in order to prosecute its claim. It explains of the difference between objections to jurisdiction and to admissibility, before providing an in-depth assessment of procedural issues, the enforcement of awards, and sovereign immunity. Finally, it assesses current issues in international investment law, including investment and the environment, corporate social responsibility, and critiques of the legitimacy of the investment treaty regime, suggesting future directions for international investment law. In addressing each of these issues the book has as its principal foundation the primary materials relevant to the topics under discussion. Presented in a clear and focused manner, this book is an essential resource for students and practitioners in the field of international investment law and arbitration.