21 December 2017

PhD: Towards a new approach to treaty interpretation


On 9 November Katayoun Hosseinnejad defended her PhD thesis in International Law, titled “Towards a New Approach to Treaty Interpretation: Interactions of Theory and Practice”. Professor Thomas Schultz presided the committee, which included Professor Zachary Douglas, Thesis Director, and Professor George Letsas, from the University College London. The inconsistency that exists in the interpretive practice of international adjudicative bodies relying on Article 31 of the Vienna Convention on the Law of Treaties forms the underlying question of Ms Hosseinnejad’s research.

Why did you decide to study treaty interpretation?

In international law, contrary to many domestic legal systems, we have rules for interpretation of treaties, which are article 31 and 32 of the Vienna Convention on the Law of Treaties. These rules, which are considered to reflect the customary law, were adopted to provide a single framework for interpretation of treaties to avoid arbitrariness. Nevertheless, by reviewing the actual usage of these rules in the practice of international adjudicative bodies, I realised that sometimes judges, on the basis of these articles, consider the grammatical structure of a sentence as a decisive factor in the process of interpretation, while in other cases, for example, the same rules are invoked to go beyond the text and to consider the intention of the drafters or the purpose of the treaty as the significant elements determining the result of interpretation. These kinds of contradictions led me to ask myself, Is this what Article 31, which is called the “General Rule of Interpretation”, provides? In other words, is it true that Article 31 does not take a stand on the doctrinal debate on treaty interpretation and therefore permits resort to the textual interpretation, as well as the intention-based interpretation, or interpretation in light of the purpose, depending on what the judges find more suitable? And if yes, does this accord with what I believe to be the underlying values of judicial interpretation, which are justice and legality?

How did you proceed to answer those questions?

With these questions in mind, I aimed to provide a new approach to judicial interpretation of treaties within the scope of Article 31. Of course, states as the subject of international law have also the authority to interpret treaties, but the focus of my research is on interpretation of treaties by adjudicative bodies because these bodies should work necessarily within the defined legal framework. My thesis can be summarised in two parts: the negative and the positive side. On the negative side, by evaluating the underlying foundations of different interpretive schools in international law (textual, intentional, teleological and contextual interpretation), I argue that although each school has something to offer to the process of interpretation, none of them by itself can guide interpreters to ensure non-arbitrariness. On the positive side, as interpretation is about finding meaning, I argue that without understanding the origin of meaning, we cannot talk about any interpretive approach. By reviewing the philosophical theories on interpretation, on the one hand, and the linguistic theories on meaning, on the other hand, I argue that it is not the bare text or the original intentions of authors that determine the meaning. Rather, the tradition and practices within a specific community determine the meanings of terms used in that community. In using the term “tradition”, it is important to note that I am not referring to the conventionalist understanding of tradition; rather, as described by Hans-Georg Gadamer, the tradition is the background that instigates all inquiry in a way that one can never start from a tradition-free place.  

The dependency of meaning upon the tradition, which is also acknowledged by major legal theorists, paves the way for providing a new reading of paragraphs 2 and 3 of Article 31. Thus, while the nature of international law requires taking into account the “conventionalist theory” to determine meaning based on the acts of the law’s subjects, the nature of interpretation and understanding requires us to understand legal terms through the mediation of the tradition that is present in a given community. I argue that these two aspects are reflected in Article 31 by, inter alia, the inclusion of “the relevant rules of international law” as referring to relevant rules as well as relevant legal tradition. I also demonstrate that the interpretive practice of international adjudicative bodies endorses this result as they have considered “relevant rules of international law” to refer to legal tradition in cases where the subject matter has not been regulated in advance.

The study on the origin of meaning also suggests that other elements listed in the first paragraph of Article 31, “good faith” and “object and purpose”, have a different role to play in the process of interpretation. I argued that Article 31 determines not only the sources in light of which the terms of treaties attain their meanings, but also the criteria for reaching a correct interpretation. Based on the nature of interpretation, in general, and the judicial interpretation, in particular, I study the implications of “good faith” in the process of interpretation as openness of judges to the claim of the text as well as limitation of their decisions to reasons provided by law. In regard to the notion of “object and purpose”, I contend that, first, the purpose that can be relied on by adjudicative bodies should be based on principle arguments and, second, without understanding the nature of a rule, its purpose cannot be properly identified especially if the purpose is to be anchored in legal principles. I borrow the concept of “not one, not two” from Zen philosophy to reject the idea that the concept of “object and purpose” is referring to one or two separate concepts. Rather, the object is at the service of the purpose pursued, and therefore its scope and meaning may be changed by the purpose identified. Conversely, the purpose is a result, which can only be achieved through the created norms, and, thus, the nature of the norm affects the purpose.

Can you give us an example of a interpretive problem and how you approach it?

Interpretation always remains central to the law because, on the one hand, in passing laws, we can never be sure about what will happen in the future. On the other hand, law portrays the world it wants to create in words. In this way, law requires the real world to be adapted to the words it uses. This implies that we can never be free from interpretation, and thus there will be no end in our effort to propose a better theory of legal interpretation. Such a need is more persistent in international law, which lacks legal institutions, in the traditional sense, and consensus over its founding legal principles to arrive at an interpretation.

But if I want to talk about a specific problem, of course, one of the most challenging issues of interpretation is the effect of time on interpretation. For example, in the Navigational Rights case decided by the International Court of Justice, Nicaragua was claiming that the term “commerce” had a special restricted meaning of purchase and sale of merchandise as existed at the time of conclusion of the treaty while Costa Rica argued that “commerce” as used in the treaty took in any activity in pursuit of commercial purposes and includes, inter alia, the transport of passengers, tourists among them, as well as of goods. Many scholars believe that the Court’s answer to this question was based on the intention of the parties since the Court justified the evolutionary interpretation of that term on the basis of the presumed intention of the parties. The correct explanation of the Court’s decision, however, is that what determined the answer was the nature of the rule and the purpose that the treaty was aimed to achieve. In other words, the juridical nature of the norm and its purpose guided the court to determine the relevant time. This means that the evolutionary interpretation of, for example, a human rights treaty does not lie in its title, but depends rather on the legal nature of the rule. And this is what the interpretive approach that I propose in my thesis provides: it demonstrates, among other things, how we reach an evolutionary or static interpretation.

Full citation of the PhD thesis: Hosseinnejad, Katayoun. “Towards a New Approach to Treaty Interpretation: Interactions of Theory and Practice.” PhD thesis, Graduate Institute of International and Development Studies, 2017.

Illustration: The Tower of Babel by Pieter Bruegel the Elder, 1563 [Public domain], via Wikimedia Commons.