In This Article Expand or collapse the "in this article" section Effectiveness and Evolution in Treaty Interpretation

  • Introduction
  • General Overviews

International Law Effectiveness and Evolution in Treaty Interpretation
  • LAST MODIFIED: 25 September 2019
  • DOI: 10.1093/obo/9780199796953-0188


Effectiveness and evolution in treaty interpretation have to be placed in the context of treaty interpretation more generally, which is one of the classical topics of public international law. For some authors, there is a link between these two elements, insofar as the principle of dynamic (or evolutive) interpretation aims to ensure the effective application and implementation of treaties. Therefore, it is appropriate to analyze them together. The majority of authors, however, concentrate on one aspect. Regarding, first of all, effectiveness, such a principle has not been explicitly enshrined in the 1969 Vienna Convention on the Law of Treaties (VCLT), but it can nevertheless be considered an underlying principle of that instrument. In particular, the flexibility of the concept of the object and purpose of a treaty allows for the consideration of effectiveness. Other tools for effectiveness are teleological interpretation and interpretation according to the effet utile (ut res magis valeat quam pereat), but neither authors nor practice systematically distinguish between those concepts and principles. In addition, judicial and quasi-judicial bodies implementing certain treaties, in particular human rights instruments and constitutive agreements of international organizations, have adopted their own principles of effectiveness, such as the principle that calls for a “practical and effective” protection of human rights or, regarding international organizations, the doctrine of implied powers. Second, the notion of evolution in interpretation raises issues of intertemporal law, namely the question as to which moment is relevant for the interpretation, i.e., the moment of the conclusion of a treaty or the moment when a dispute necessitating interpretation arises. The analyzed literature shows that, generally speaking, practice and theory seem to favor a dynamic and evolutive interpretation within appropriate and reasonable limits, justifying such an approach, inter alia, by the special nature of certain treaties. As far as the relevant practice of international courts is concerned, human rights tribunals, in particular the European and the Inter-American Court of Human Rights (ECtHR and IACtHR), both adopting a dynamic and effective interpretation, have received significant doctrinal attention in this regard. For the authors, the special nature and purposes of those treaties justify a flexible, evolutive, and effective approach. The same can be said for the Court of Justice of the European Union, having relied heavily on interpretation according to the effet utile of a treaty. The practice of the Permanent Court of International Justice (PCIJ) and the International Court of Justice (ICJ), both dealing with inter-State complaints, are not surprisingly less nuanced concerning effectiveness and evolution, but have nevertheless shown a clear trend in that direction more recently. Finally, the analysis of the practice of the World Trade Organization (WTO) Appellate Body, which deals with inter-State claims too, is more ambiguous, but it is generally suggested that its interpretation is less guided by considerations of effectiveness and evolution than, inter alia, the practice in the field of human rights.

General Overviews

Even though the principle of effectiveness was finally not included explicitly in Article 31 of the 1969 Vienna Convention on the Law of Treaties (VCLT), it is often considered an underlying principle in that norm (see Dörr 2012 and Sorel and Boré Eveno 2011). Moreover, it is sometimes said to be reflected in the object and purpose, or in good faith (Dörr 2012, Gardiner 2012, and Orakhelashvili 2008), but there is no agreement on how effectiveness, effet utile, object and purpose, and teleological and dynamic interpretation interact between each other exactly (see, in particular, Sorel and Boré Eveno 2011). The question is also raised whether the object and purpose is something static or whether it is subject to evolution (see Yasseen 1976). In other words, is the relevant intention of the parties to be considered as that existing on the moment of the conclusion of a treaty or at some point in the future (see Alland 2012)? Certain authors recognize in the practice of contemporary actors, in particular international organizations, a source for legitimate law-making (Venzke 2012). Others underline the specificities of certain types of treaties and indicate the limits of teleological interpretation, criticizing a disproportionate reliance on the object and purpose, in particular in human rights treaties, which might exceed the limit between legitimate interpretation and problematic law-making (see Sinclair 1984 and Herdegen 2013).

  • Alland, Denis. “L’interprétation du droit international public.” Recueil des Cours 362 (2012): 41–394.

    Approaches intertemporal law under two aspects, namely evolutive treaty interpretation and the definition of the intention (or will) of the parties concerning the meaning to be given to a certain term of a treaty. Distinguishes between the past and the future intention (or will) of the parties, expressed in the travaux preparatoires and the subsequent practice, respectively.

  • Dörr, Oliver. “Article 31: General Rule of Interpretation.” In Vienna Convention on the Law of Treaties: A Commentary. Edited by Oliver Dörr and Kirsten Schmalenbach, 521–570. Heidelberg, Germany: Springer, 2012.

    DOI: 10.1007/978-3-642-19291-3_34

    Useful discussion of the temporal element of interpretation, including both the static and dynamic approaches. Recalls that the principle of effectiveness has not been included in Article 31 § 1 of the VCLT, but that it can be regarded as a mere application of the object and purpose test and the good faith rule. Useful analysis of the object and purpose of a treaty.

  • Gardiner, Richard. “The Vienna Convention Rules of Treaty Interpretation.” In The Oxford Guide to Treaties. Edited by Duncan B. Hollis, 475–506. Oxford: Oxford University Press, 2012.

    Explains why he does not consider interpretation in the light of the object and purpose of a treaty to be a rule in the sense of a prescriptive formula, but rather an indication of a factor to be considered. Explains how the object and purpose relate to the principle of effectiveness, which contains a narrow and a broader aspect. Discusses whether the duty to take into account any relevant rules of international law applicable in the parties’ relations tends to favor an evolutive interpretation.

  • Herdegen, Matthias. “Interpretation in International Law.” In Max Planck Encyclopedia of Public International Law. Edited by Rüdiger Wolfrum. Oxford: Oxford University Press, 2013.

    Provides brief but useful considerations of the concept of object and purpose as well as on effectiveness (effet utile). Argues that teleological interpretation, according to the object and purpose of the treaty, may easily become the vehicle for a dynamic interpretation. Singles out some rules for specific types of treaties, namely constituent treaties of international organizations, human rights treaties, World Trade Organization (WTO) treaties, and treaties on investment protection. Devotes a short, critical section to the borderline between dynamic interpretation and law-making.

  • Orakhelashvili, Alexander. The Interpretation of Acts and Rules in Public International Law. Oxford: Oxford University Press, 2008.

    DOI: 10.1093/acprof:oso/9780199546220.001.0001

    In the chapter on interpretation in international law, the author addresses the object and purpose of a treaty together with the principle of effectiveness. The latter concept is contrasted with the principle of restrictive interpretation, the presumption of redundancy, as well as the interpretation of exceptions. The authors recognizes in the implied powers of international organizations and the inherent powers of international courts the institutional implications of effectiveness.

  • Sinclair, Ian. The Vienna Convention on the Law of Treaties. 2d ed. Manchester, UK: Manchester University Press, 1984.

    See also the separate Oxford Bibliographies article Treaty Interpretation. A reissue of the 1961 edition (first published in 1938). One of the classics in the field of treaty law. Devotes a chapter (chapter 5) to the interpretation of treaties and, therein, an important part to the object and purpose of an instrument. Critical analysis of the early case law of the European Court of Human Rights.

  • Sorel, Jean-Marc, and Valérie Boré Eveno. “Article 31 of the Convention of 1969.” In The Vienna Conventions on the Law of Treaties: A Commentary. Vol. 1. Edited by Olivier Corten and Pierre Klein, 804–837. Oxford and New York: Oxford University Press, 2011.

    The authors recall the travaux préparatoires of Article 31 of the VCLT, including of a draft provision referring explicitly to “effectiveness,” which was abandoned in later drafts. They suggest that effectiveness is implicit in good faith and in interpretation in the light of the object and purpose. Point out the silence, within Article 31 § 1 of the Vienna Convention, on intertemporal law and explain the reasons for this.

  • Venzke, Ingo. How Interpretation Makes International Law: On Semantic Change and Normative Twists. Oxford: Oxford University Press, 2012.

    DOI: 10.1093/acprof:oso/9780199657674.001.0001

    In this remarkable, thoughtful work, the author shows how interpretation can shift the meaning of international law. It is argued that, through their interpretative practice, international actors debate and develop the sources of international law, treaties as well as customary law, and contribute to creative law-making. The key examples discussed are the practice of the UN High Commissioner for Refugees (UNHCR) and the WTO Appellate Body. See also Venzke 2012 under WTO Appellate Body.

  • Villiger, Mark E. Commentary on the 1969 Vienna Convention on the Law of Treaties. Leiden, The Netherlands: Martinus Nijhoff, 2009.

    DOI: 10.1163/ej.9789004168046.i-1058

    See also the separate Oxford Bibliographies article Treaty Interpretation. The author presents, very concisely, the main aspects of the term “object and purpose,” suggests where the object and purpose might be sought, and indicates the limits of the interpretation of a treaty in the light of its object and purpose. Also refers to teleological or functional interpretation, as well as to the effectiveness of a treaty.

  • Yasseen, Mustafa K. “L’interprétation des traités d’après la Convention de Vienne sur le droit des traités.” Recueil des Cours 151 (1976): 1–114.

    See also the separate Oxford Bibliographies article Treaty Interpretation. The author devotes a chapter to the concept of the object and purpose of a treaty, its definition, determination, scope and function, as well as to the question of whether it is subject to evolution or, on the contrary, has to be interpreted as something static. Another chapter explains the concept of effet utile (ut res magis valeat quam pereat). See also Yasseen 1976 under Effectiveness: Object and Purpose, Teleological Interpretation, and Effet Utile.

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