Treaty Interpretation: Reviewing the Rules

I am most grateful for this opportunity to thank Opinio Juris for hosting discussion of Treaty Interpretation and, in particular, Duncan Hollis for setting up the event.

The rules of treaty interpretation codified in the 1969 Vienna Convention on the Law of Treaties, Articles 31-33, have now been around for 40 years, but only in the last 15 has their use become quite widespread. Too much should not be expected of the Vienna rules. Their progenitors in the ILC deliberately avoided going beyond “trying to isolate and codify the comparatively few general principles which appear to constitute general rules for the interpretation of treaties.” (Commentary on draft articles).

Brief though the Vienna rules are compared with the comprehensive canons drawn up by others, their application in any given case can be a lengthy exercise. Just exploring the context requires considering the whole text of the treaty (and more); the rest of the general rule may require exploring practice, whole areas of international law, (and more); the preparatory work may be extensive (and there are other supplementary means as well); and language comparisons all too often throw up points of importance.

The only other show in town at the time of the 1969 Vienna Convention was the contrasting approach of the McDougal/New Haven School. Key features (greatly oversimplified) of this were: viewing an international agreement as a continuing process of communication and collaboration between the parties, examining context in a much broader sense than that defined in the Vienna rules, finding the shared expectations of commitment, and taking into account community values.

Review of this approach suggests several questions:

1) Has the “tragedy” which McDougal foresaw in the Vienna rules of an “insistent emphasis upon an impossible, conformity-imposing textuality” (61 AJIL 992 (1967)) proved justified?

2) Would such a tragedy have been averted by adoption of the system in his (and his collaborators’) massive work on interpretation of agreements?

3) Has recourse to the preparatory work of treaties been unduly curtailed?

4) Would the New Haven system have proved a scheme better fitted to the purpose?

Suggesting the answer no to each of these questions (in the case of the second one, on the basis that the tragedy has not occurred), there are nevertheless several issues which warrant another look. Picking out just a couple, the extent of preparatory work to be considered and how to use it remain difficult matters. Underlying the recent OJ blog about treaty provisions on piracy (One Solution to Piracy: Try Pirates in Kenya) was the issue whether admissible ILC material was limited to its very brief commentary or whether, at the other extreme, one should follow up the ILC’s acknowledged lifting of piracy provisions from the 1932 Harvard draft articles? Should preparatory work be investigated only to identify agreement among the negotiators or, particularly in the case of treaty provisions with a codifying aspect, to assess the state of international law leading up to the treaty and how this affected the negotiators?

The case of Witold Litwa v Poland in the ECtHR offers an example suggesting that excessive textuality and the supplementary role of preparatory work are not obstacles introduced by the Vienna rules into the interpretative process. The judgment in that case held that detention of someone who had been found drunk was permitted by the exception in the Human Rights Convention allowing detention of “alcoholics”. But did the Court give the Vienna rules a formalistic and unrealistic application to produce a meaning not limited to persons addicted to alcohol but just plain drunk? Was the Court really using the preparatory work to determine the meaning while pretending that the conclusion could be reached within the ambit of the general rule of interpretation?

One case is no basis for a general conclusion, but there are grounds to hope that the Vienna rules provide a useful framework, setting fair bounds to the investigation of meaning without insisting on “an impossible, conformity-imposing textuality”.