A preliminary observation relates to the formalities of debating a question such as the present; in such a situation, the best way to win the debate is to interpret the motion such that you cannot lose. Those speaking for the motion have defined “expansive” as meaning undue or excessive, and no one would disagree with that proposition if that is the correct interpretation.

But on that basis, the motion is analogous to the famous question “Have you stopped beating your tribunal?” That is because, in the real world, there are few decisions of tribunals that are so manifestly excessive that everyone would reject them. We are, instead, in the realm of the arguable, and there are some lessons to be drawn from particular cases.

Let me take three examples where courts or tribunals interpreted their mandate perhaps more broadly than they might have done, but in the course of doing so, actually resolved the dispute:

• – the first is the decision by the ICJ in the Peru v. Chile case to decide the location of the land boundary terminus;

• – the second is the assertion of jurisdiction in the ARA Libertad (Argentina v. Ghana) over the arrest of a warship in internal waters. There were very strong arguments for saying that the Tribunal's decision was in excess of jurisdiction, but it nevertheless resolved the dispute;

• – third is the ICJ's assertion of jurisdiction, rather associated with the distinction between jurisdiction and applicable law, in the Bosnian Genocide case, which enabled the court to arrive at an answer—whether or not you agree with it—on the basis of interpretation.

In short, taking the question in a debatable way, rather than in an undebatable one, it is whether there are special rules of interpretation of compromissory clauses. The argument for saying that there are is, with respect, not a strong one: they are treaties, and they have to be interpreted like treaties. There may be occasions when a broad interpretation, or an effective interpretation, is called for. Of course, not an expansive interpretation—that would be intolerable—but something perhaps slightly less, but nonetheless real.

It is also instructive to look at cases in which states have changed their jurisdictional position after decisions with which they disagree. Here, it is not obvious that there is any particular difference between changes in the jurisdictional status of the aggrieved state as between jurisdictional decisions and merits decisions. For example, the United Kingdom changed its optional clause declaration after the decision in the Marshall Islands case, a case that it won! The United States, as a result of the Avena and related cases, withdrew from the Optional Protocol to the Vienna Convention on Consular Relations; it didn't like the outcome of the case, but it is doubtful whether that was a jurisdictional matter. Colombia withdrew from the Pact of Bogotá on grounds I believe essentially unrelated to jurisdiction and more related to merits. So it is not obvious that jurisdictional decisions form a universe of their own in relation to “horrible things in international law,” as one might describe them, as perceived by the “losing” party.

In my view, the Court in Libya/Malta got it right when it said that it should exercise jurisdiction to the fullest extent justified by the language of the relevant clause. That is a more balanced proposition than the proposition that restrictive interpretations should always be applied.