Introduction

In international dispute settlement proceedings, respondents often argue, as a first line of defence, that one or more of the claims either are inadmissible, or fall outside of the jurisdiction of the international court or tribunal. In contentious proceedings before, for example, the International Court of Justice, a judgment on the merits is frequently preceded by a separate judgment addressing the respondent's objections on admissibility and/or jurisdiction; likewise, rulings on admissibility and/or jurisdiction are a ‘standard feature’ in the context of investor–State disputes. The issues relating to admissibility and jurisdiction that arise most frequently in the context of WTO dispute settlement are derived from specific provisions of the DSU. These provisions do not embody concepts or principles of general international law, which makes WTO jurisprudence related to those specific provisions of limited relevance or applicability in other contexts. This chapter reviews statements of wider applicability by WTO adjudicators relating to other issues of admissibility and jurisdiction. International decisions ‘are replete with fine distinctions between jurisdiction and admissibility’. It is not clear that the distinction between admissibility and jurisdiction carries any legal implications in the context of WTO dispute settlement, and this may explain why it has not been discussed by panels and the Appellate Body (and why it would seem that the two terms have sometimes been used interchangeably by WTO adjudicators). The first part of this chapter reviews, under the rubric of the ‘admissibility of claims’, statements by WTO adjudicators on: (i) restrictions on admissibility not being lightly inferred; (ii) acquiescence, estoppel and waiver; (iii) absence of legal interest/standing; (iv) failure to implead an ‘essential party’; (v) failure to join cases; (vi) failure to exhaust local remedies; (vii) forum non conveniens; and (viii) res judicata. The second part of this chapter reviews, under the rubric of the ‘jurisdiction over claims’, statements by WTO adjudicators on: (i) the rule governing claims falling outside of a tribunal's subject-matter jurisdiction; (ii) implied restrictions arising from overlapping jurisdictional competencies among different bodies;