International custom is one of the main sources of international law. As a relatively new branch of international law, international investment treaties, emerging in the late 1950s and having been very energetic since the mid-1990s, have become a driving force and an important forum for the formation, application and transformation of the customary international law rules.

Patrick Dumberry provides a comprehensive analysis of the rules of customary international law in the field of international investment law.

General international law is part and parcel of investor-state arbitration. This is the case not only regarding treaty law and state responsibility, but also with respect to matters such as state succession, the international minimum standard, and state immunity, all of which feature regularly in investor-state arbitration. Yet, although general international law issues arise in almost every investment case and often require extensive research, no systematic exploration of the relationship between the two exists. This Commentary is the first to fill this gap, providing a comprehensive treatment of the role of general international law in international investment law. It engages in detail with central matters of general international law, including in the practice of investment arbitration tribunals, moving beyond existing works which focus solely on procedural and institutional provisions. The Commentary's forty-six chapters do not focus on a single source or subject. Instead, each concentrates on a specific, relevant article from a particular source of public law - such as the Vienna Convention on the Law of Treaties (1969) or the International Law Commission's Articles on the Responsibility of States for Internationally Wrongful Acts (2001), among others. The entries combine detailed analysis with an examination of procedural and substantive aspects - such as nationality and unjust enrichment - and respond to the following questions: how have investment tribunals interpreted and applied the specific rule of general international law? To what extent and why does such interpretation and application align with or deviate from the practice by other international courts or tribunals? How could and should investment tribunals interpret and apply rules that have yet to feature in investment arbitration? This unique format means this commentary will serve as a central guide for all relevant case law and scholarship on international investment law.

At first glance, one may think of international investment law as a response to custom (or lack thereof), instead of a field of its application. However, in fact, the opposite is the case. The interpretation and application of customary rules and principles are the bread and butter of international investment law and arbitration. With a diverse range of expert contributors, this collection traces how customary international law is practised in international investment law. It considers how custom should be interpreted and how its rules and principles should be understood and applied by investor-state arbitral tribunals. Raising and addressing vital questions surrounding custom and international law, this collection is a necessary contribution to the scholarship of the theory and history of customary international law and international investment law. This title is also available as Open Access on Cambridge Core.

In 2005, as part of its research activities in the field of investment treaty law and arbitration, the Investment Treaty Forum at the British Institute of International and Comparative Law organized two very successful public conferences in London addressing the issues of 'Nationality and Investment Treaty Claims' and 'Fair and Equitable Treatment in Investment Treaty Law.' This publication records the presentations given by very distinguished experts in the field. The first conference addressed a central issue in international law. Nationality sits at the heart of the debate over the rights and participation of private parties in international relations. In international investment law, nationality constitutes one of the central criteria defining the scope of application of international investment agreements such as the International Centre for Settlement of Investment Disputes (ICSID) Convention or the several thousands bilateral investment treaties (BITs) and free trade agreements (FTAs). Topics addressed at the conference include the issue of nationality of physical and legal persons, the requirements for substantive and continuous nationality, as well as the issue of nationality in derivative actions and indirect claims. The second conference dealt with potentially the most important and elusive obligation imposed on States by international investment treaties: the fair and equitable treatment standard. The elements that are usually cited by the case law and by legal scholars in the attempt to describe the meaning of the fair and equitable treatment standard include very broad concepts that are open to differing interpretations depending fundamentally on the perceived objectives of the international investment system. Among the topics addressed at the conference were the application of the fair and equitable treatment standard in customary international law and in investment treaty practice; equivalent standards under domestic administrative law; the relationship between the fair and equitable standard and expropriation; and the relevance of the conduct of the investor in determining a breach of the fair and equitable treatment standard.

Transnational investment involves a variety of actors (States, public and private legal entities, and natural persons) whose relationships are governed by rules and legal instruments belonging to different legal systems. This book provides a systematic study of the sources of rights and obligations in the field of transnational investment, and their coordination and interaction. It focuses primarily on the network of over 3,000 Bilateral Investment Treaties, international investment contracts, customary international law, the main multilateral treaties, national legislation, international case law and general principles of law. The book, firmly based on State practice, arbitral awards and national decisions, is indispensable to fully appraise the nature and content of the claims of private investors as well as to identify the law applicable in investment arbitration.

International investment law is one of the fastest growing areas of international law. It has led to the signing of thousands of agreements, mostly in the form of investment contracts and bilateral investment treaties. Also, in the last two decades, there has been an exponential growth in the number of disputes being resolved by investment arbitration tribunals. Yet the legal principles at the basis of international investment law and arbitration remain in a state of flux. Perhaps the best illustration of this phenomenon is the wide disagreement among investment tribunals on some of the core concepts underpinning the regime, such as investment, property, regulatory powers, scope of jurisdiction, applicable law, or the interactions with other areas of international law. The purpose of this book is to revisit these conceptual foundations in order to shed light on the practice of international investment law. It is an attempt to bridge the growing gap between the theory and the practice of this thriving area of international law. The first part of the book focuses on the 'infrastructure' of the investment regime or, more specifically, on the structural arrangements that have been developed to manage foreign investment transactions and the potential disputes arising from them. The second part of the book identifies the common conceptual bases of an array of seemingly unconnected practical problems in order to clarify the main stakes and offer balanced solutions. The third part addresses the main sources of 'regime stress' as well as the main legal mechanisms available to manage such challenges to the operation of the regime. Overall, the book offers a thorough investigation of the conflicting theoretical positions underlying international investment law, testing their worth by reference to concrete issues that have arisen in the jurisprudence. It demonstrates that many of the most important practical questions arising in practice can be addressed by a carefully dosed resort to theory.

The rapid growth in investment treaties has led to a burgeoning number of international arbitration decisions that have applied and interpreted treaty provisions in disputes between investors and states concerning their respective rights. This flurry of treaties and arbitral decisions has seen the creation of a new branch of international law- the law of investment claims. In this revised edition, Jeswald Salacuse examines the law of international investment treaties, specifically in relation to its origins, structure, content, and effect, as well as their impact on international investors and investments, and the governments that are parties to them. Investment treaty law is a rapidly evolving field and since publication of the first edition, the law of international investment treaties has both experienced considerable growth and generated extensive controversy. 2011 saw the highest number of new treaty-based arbitration filed under international investment agreements to date, and in July 2014, the Yukos Universal Limited (Isle of Man) v The Russian Federation culminated with awards of over US$50 billion; a historic record for any arbitration. Controversy in this field has primarily revolved around the investor-state dispute settlement process, which as thus far involved at least 98 states as respondents. Salacuse captures these developments in this updated edition, examining not only the significant growth in treaties, but the trends that have followed, and their effect on the content and evolution of the law of investment treaties. Specific topics include conditions for the entry of foreign investment and general standards of treatment of foreign investments; monetary transfers; operational conditions; protection against expropriation; dispossession and compensation for losses; dispute settlement, including negotiation, arbitration, and conciliation; and judicial proceedings.

The author examines different techniques adopted by States for attracting foreign investment and for ensuring that foreign investment serves their economic objectives.

'...This book [...] goes beyond stating what the law is and focuses on controversies occurring within this area of the law... an excellent introduction to this complex area of international law for newcomers to the subject' Kate Miles, Australian International Law Journal The updated edition of this acclaimed book offers a critical overview of the law of foreign investment, incorporating a thorough analysis of the principles and standards of treatment available to foreign investors in international law. It is authoritative and multi-layered, offering an analysis of the key issues and an insightful assessment of recent trends in the case law, from both developed and developing country perspectives. A major feature of the book is that it deals with the tension between the law of foreign investment and other competing principles of international law. In doing so, it proposes ways of achieving a balance between these principles and the need to protect the legitimate rights and expectations of foreign investors on the one hand, and the need not to restrict unduly the right of host governments to implement their public policy on the other, including the protection of the environment and human rights, and the promotion of social and economic justice within the host country. Many of the pioneering ideas that were advanced in the first edition of this book have been taken up by governments and international organisations in their attempts to reform the investor-State dispute settlement mechanism and strike a balance between different competing principles in developing international investment law. Accordingly, this fifth edition captures the essence of the ongoing multiple reform processes – either planned or envisaged – currently underway.