Most writings about treaty interpretation in international law are about how treaty interpretation should proceed and how treaty interpreters are constrained by various rules that discipline the interpretive exercise. Chapter 1 showed why rules by themselves cannot determine what treaty interpretation is and how it should proceed. This does not mean, however, that international lawyers are wrong in their self-perception that treaty interpretation is a constrained activity. This chapter argues that international lawyers have been looking for the source of interpretative constraints in the wrong place and that the actual interpretive constraints come from the fact that treaty interpretation is never the work of an isolated interpreter, but an exercise performed by a member of an interpretive community that determines what counts as a legitimate interpretation.

Despite the fact that the Vienna Convention prescribes a holistic approach to treaty interpretation, it is widely believed that the dominant interpretive approach in international law is textualism. Textualism is premised on the distinction between what is inside and what is outside the text of a treaty and assumes that it is possible to interpret a text without reference to factors that are extraneous to it. This chapter situates the preference for textualism in the intellectual history of the discipline. Building on philosopher John Searle’s work, it argues, however, that no treaty interpreter is or can be a textualist. It also introduces the concept of intertextuality and discusses the tension between the official functions of textualism and the practice of treaty interpretation.

Demystifying Treaty Interpretation doesn’t just tell you how treaties are commonly interpreted. It helps you understand the process of treaty interpretation and its outcomes. The idea that rules of treaty interpretation can guide us to the meaning of treaty provisions, in a simple and straightforward manner, is a myth to be dispelled. This book aims to capture some of the complex and nuanced processes involved in treaty interpretation. It spurs further reflection about how interpretation takes place against the background of concepts, categories, and insights from other disciplines. A useful tool for scholars, practitioners, and researchers engaging with treaty interpretation at all levels, the book aims to enhance the reader’s knowledge and mastery of the interpretive process in all its elements, with a view to making them more skilled and effective players in the game of interpretation.

This chapter frames the interpretive regime of modern international law as a historical contingency and aims to trace its genealogy through an analysis of the codification process that led to the current regime. The contingency of the rules of treaty interpretation is hardly recognized in the official discourse. Treated as a matter of common sense or trans-historical customary international law, the rules of treaty interpretation set forth in the Vienna Convention on the Law of Treaties have for instance been applied to the interpretation of treaties dating back to the nineteenth century and a whole range of treaties concluded in the twentieth century before the entry into force of the Vienna Convention. There is, however, ample evidence that the interpretive approach of the Vienna Convention has by no means prevailed throughout the history of international law. This chapter identifies a series of factors ranging from the intellectual history of the discipline of international law and the contingencies of the codification process, to the political circumstances of the Cold War era and the rise of permanent international tribunals that can account for the normative outcome of the Vienna Convention regime.

The rules of treaty interpretation of the Vienna Convention on the Law of Treaties have a special status in international law, dominating the vocabularies and minds of international lawyers. They are ubiquitous – they are always visible, regardless of where one stands in the international legal arena, and they also provide for a sense of community amongst scholars and practitioners, who are constantly reassured by their presence. This chapter argues that it is illusory to believe that the function of the rules of treaty interpretation is to directly bridge the gap between the signifier (treaty provision to be interpreted) and the signified (the meaning of the treaty provision). In fact, ‘rules’ are not determinative of meaning. They only aim to impose a ‘common discipline’ with respect to the admissible ‘sources of interpretive data’ that can be used in treaty interpretation. Furthermore, as there is no unmediated access to any signifier, the rules of interpretation are themselves subject to interpretation. The chapter concludes by shifting the attention from the rules of treaty interpretation to the notion of interpretive authority as a useful complement to understanding the process of treaty interpretation.

Systemic integration has made its way into the parlance and practice of international scholars and adjudicators, particularly as a tool against the fragmentation of international law. The chapter analyses it as a particular instance of what Foucault termed ‘problematization’, that is, ‘how and why certain things (behavior, phenomena, processes) became a problem’. In fact, while the issue of fragmentation is not a recent phenomenon, only in the late 1990s did it receive special attention. Why was it so? The question of what drove most international lawyers to present fragmentation as one of the most pressing issues of the time, and the International Law Commission to issue a report on fragmentation and international law, prepared by Martti Koskenniemi in 2006, is examined. The chapter argues that the wide acceptance of the systemic integration principle could be explained by international lawyers’ continuous quest for unity, uniformity, and coherence.

Authors are commonly thought to have a privileged position when it comes to the interpretation of their texts. Since treaties are consensual instruments, it is not surprising that the parties have a say in the interpretation of their treaties. At the same time, treaties cannot escape what is the fate of every text: the possibility to read a text in the absence of its author is structurally inscribed in it. This chapter examines the ways in which the parties can influence treaty interpretation in various phases of the life of the treaties. It also accounts for the diminishing state authority in the modern practice of treaty interpretation.

This chapter looks at interpretation as a game aimed at persuading an audience and securing its adherence to a given interpretation. Like the other chapters, it analyses certain elements that cannot be traced back to or explained by the rules of interpretation of the Vienna Convention on the Law of Treaties. Its focus is on the broader concepts of persuasion, audience, and interpretive acceptability. It argues that the acceptability (or unacceptability) of a certain interpretation is not inherent in the interpretation itself, but rather hinges on the social environment where the interpretation is articulated or received. This is why the success of a certain interpretation can be measured, to a large extent, by its ability to persuade the relevant audience. The latter, in turn, is dependent on the interpretive authority wielded by the actors involved in the process and on the latent power structures underlying the interpretative game. Interpretation constitutes a fight to speak authoritatively in and for the discipline, a process in which not all voices carry the same weight, and where different interpretive strategies can be framed as tools to control the discursive politics of interpretation in international law.

Building on Derrida’s celebrated analysis of the term ‘supplement’, this chapter investigates the fundamental ambivalence of supplementary means of treaty interpretation. While the general philosophy of the Vienna Convention interpretive regime rests on the assumption of a hierarchy between the primary means set forth in Article 31 of the Vienna Convention and the supplementary means of Article 32, qualifying certain means as supplementary presumes that the primary interpretive means are somewhat lacking and in need of a complement. The chapter also focuses on the ‘danger’ of such supplement that has been highlighted in practice, namely, that supplementary means themselves need to be interpreted before they can be used in an interpretive inquiry, reinforcing the larger point made in the book that it is impossible to get an unmediated access to any signified. The chapter argues that since supplementary means are not comprehensively listed in the treaty interpretation regime, a virtually endless number of materials can be made relevant in treaty interpretation discourse through the channel of supplementary means.

Intentionalism is the least investigated approach to treaty interpretation. It is often discredited by international legal scholars on the basis of various pragmatic arguments. It is also normatively discouraged as a threat to the stability and predictability of treaty rules. At the same time, even a cursory glance at the case law of international courts and tribunals would be sufficient to realize that treaty interpretation discourse in practice is replete with references to the parties’ intention. This chapter situates the reluctance of international legal scholars about intentionalism in the broader intellectual history of international law and shows that most objections to intentionalism rest on a mentalist understanding of intention that has been severely criticized in philosophy. It also argues that given intentionalism’s close connection with consensualism, it is unrealistic to believe that it can be dismissed in practice.

Implying rights and obligations that are not explicitly set forth in a treaty is not a technique of treaty interpretation explicitly recognized in the Vienna Convention. But the practice of treaty interpretation supplies numerous examples of interpretively implied consequences of express treaty commitments. This chapter focuses on some of the best-known examples of treaty interpretation based on necessary implications ranging from the theory of implied powers of international organizations to the doctrine of positive obligations in international human rights law. Building on philosopher Robert Brandom’s theory of inferentialism, it argues that what is presented as necessary implications in treaty interpretation are discursively articulated inferential consequences of formal commitments undertaken under the treaty.

There are a number of ways in which time affects treaty interpretation. This chapter examines how a text can be understood, in Roland Barthes’s famous expression, as a ‘weapon against time’ (i.e. a device of stability). In international law, such understanding of a text as a safeguard against change is rooted in the principle of contemporaneity, according to which the terms of a treaty shall be interpreted according to the meaning prevailing at the time of its conclusion. Nevertheless, an exception to this principle has emerged in the form of the doctrine of evolutionary interpretation. This chapter thus looks at the ways in which lawyers navigate the tensions between stability and the perceived need for law to respond and adapt to changing social circumstances and present-day conditions. The chapter then turns to the question of subsequent practice and, more precisely, what should be meant by ‘practice’. It also seeks to illuminate the stakes of the debate about the ultimately rejected draft Article 38 of the Vienna Convention, which provided for the possibility of the modification of a treaty by subsequent practice. Finally, the chapter also broaches the question of the boundary between interpretation, law-making, and the emergence of a new rule of customary international law.

How does one ascertain the object and purpose of a treaty? Can a treaty have more than one object and purpose? What does giving effect to the object and purpose of a treaty mean in practice? Despite such fundamental uncertainties surrounding them, the ‘object and purpose’ are widely resorted to in the practice of treaty interpretation. This chapter argues that the object and purpose doctrine is coextensive with a large amount of interpretive discretion. The identification of the object and purpose of a treaty a largely indeterminate process, and the assumption that the treaty makers necessarily want the object and purpose of their treaty to be implemented under all circumstances leaves the treaty interpreter with considerable normative power that can hardly be resisted given the very terms of the assumption. The chapter argues that consideration of the finality of a treaty cannot be an exercise in abstract logic, but meet the requirements of practical reason.