The author seeks to illustrate the multiplicity of thoughts and varied techniques deployed in interpreting consent in investment arbitration. The chapter shows that the steady rise of varied international disputes has generated significant debate about the interpretation and application of the principle of consent. International courts and tribunals are being increasingly criticized by States for their jurisdictional overreach. The underlying problem, as the author sees it, may well be whether the contours of consent to arbitration are clear. Investment arbitration tribunals while dealing with the question of State consent have shown sharp divisions on the notion of consent. The varied approaches taken by arbitral tribunals to State consent highlights the indeterminacy of the contours of consent. The chapter finds support for its argument in a case study of the issue of State consent in the context of the interpretation of Most-Favoured Nation clauses.

In the decades before the First World War, Europeans developed new institutions and information networks to try to understand and manage a rapidly changing world economy. This was a diffuse organizational web without a clear institutional centre, but it was grounded in an increasingly standardized and professionalized set of treaty practices. This chapter traces Lucien Coquet, Hubert Llewellyn Smith, Bernhard Harms, and Richard Riedl as they began to build careers in a globalizing economy that was marked by sharp social and political tensions.

In the early 1920s, Hubert Llewellyn Smith took the lead in developing a new framework for multilateral trade policy in the Economic Committee of the League of Nations. He integrated the existing bilateral treaty regime into the League by imposing new forms of international oversight and standardization – most notably by codifying the most-favoured-nation norm. He also crafted a new rule-making routine to support the development of standalone multilateral agreements on key topics such as customs administration. Llewellyn Smith worked hard to preserve the status of the British Empire as an autonomous but segmented sub-unit within the League but he also understood that doing so would constrain Britain’s leadership capacity. Consequently, he aired on the side of caution, seeking consensus, working incrementally, and avoiding bold provocation. His limited ambitions allowed him to focus on crafting a new multilateral process, with important consequences for the subsequent history of international trade policy in the interwar period and beyond.

Following the finding in Chapter 3 that reciprocity encounters limitations when the subjects of a legal relationship are not equal, this chapter analyses the role of reciprocity in rules pertaining to the treatment of individuals in international law, assessing how reciprocity functions differently depending on who rights are owed to in different substantive areas of law. First looking at historical standards of treatment including those based on reciprocity and the use of the minimum standard of treatment, the chapter goes on to examine how reciprocity functions in national treatment and the most-favoured nation clause. The chapter then goes on to examine the treatment of individuals under human rights, international humanitarian law, and international investment law, analyzing the differences that arise in the role of reciprocity when the legal obligations in question are owed directly to individuals. The chapter ends with an examination of recent developments in diplomatic protection.