On 8 October 2007, the International Court of Justice delivered its judgment in the Case Concerning Territorial and Maritime Dispute between Nicaragua and Honduras in the Caribbean Sea. The Case involved a dispute between Nicaragua and Honduras over the delimitation of their maritime boundary, as well as a sovereignty dispute over certain islands and cays adjacent to their coasts. The case was brought to the Court by Nicaragua in December 1999 on the basis of the American Treaty of Pacific Settlement (the Pact of Bogotá) and the so-called optional clause in Article 36(2) of the ICJ Statute.
In its Application, Nicaragua asked the Court to “determine the course of the single maritime boundary between the areas of territorial sea, continental shelf and exclusive economic zone appertaining respectively to Nicaragua and Honduras, in accordance with equitable principles and relevant circumstances recognized by general international law as applicable to such a delimitation of a single maritime boundary.” It is notable that the Application did not refer to any questions of sovereignty over islands or cays in the Caribbean Sea. From a formal point of view, this was a new claim introduced in the course of the proceedings. Nevertheless, the Court held that it was necessary to decide the sovereignty dispute in order to delimit the maritime boundary. The Court held that “the Nicaraguan claim relating to sovereignty over the islands in the maritime area in dispute is admissible as it is inherent in the original claim relating to the maritime delimitation between Nicaragua and Honduras in the Caribbean Sea” (para. 115 of the Judgment). It is interesting to note that the name of the Case has in fact changed. Throughout the proceedings, the case was referred to as the “Case Concerning the Maritime Delimitation between Nicaragua and Honduras”. The title of the final judgment, however, reflects the wider issues dealt with by the Court.
Proceeding to the merits, the Court first considered the various claims to sovereignty over Bobel Cay, South Cay, Savanna Cay and Port Royal Cay as well as other islands, rocks, banks and reefs in the disputed maritime area. The Court found that the doctrine of uti possedetis, although potentially applicable to the dispute, did not afford adequate assistance in determining sovereignty over the islands. It then considered the doctrine of effectivités and decided that Honduras had shown a sufficient overall pattern of conduct to demonstrate its intention to act as sovereign over the islands (see para. 208 of the Judgment).
The Court then went on to delimit the maritime boundary between the two States. The Court noted that the UN Convention on the Law of the Sea (LOS Convention) was applicable to both parties to the dispute and it bases much of its reasoning on the relevant provisions of the Convention. It summarily dismisses the fact that the Convention was not binding on Nicaragua when the case was submitted to the Court and the fact that the Application asked for the Court to delimit the boundary on the basis of general international law (see para. 261 of the Judgment). It may be that the LOS Convention largely reflects general international law, but the Court does not address the issue in any detail.
A wider question raised by the dispute is whether or not the Court would have been able to settle the dispute if it had been raised under the dispute settlement clauses of the LOS Convention. The jurisdiction of a court or tribunal seised under the LOS Convention is limited to “any dispute concerning the interpretation and application of [the] Convention which is submitted to it in accordance with this Part” (see Article 288(1) of the Convention). Whilst maritime delimitation is undoubtedly within the scope of the LOS Convention – albeit subject to optional exclusions in Article 298 – sovereignty over land territory is not. In these circumstances, would a court or tribunal acting under the LOS Convention be able to settle the dispute? Is it possible to separate the maritime delimitation dispute from the sovereignty dispute in this case? Does Article 293 of the LOS Convention allow a court or tribunal to settle territorial sovereignty claims which are inherently related to disputes over maritime delimitation?
Similar issues were raised in the recent award by an arbitral tribunal seised of a dispute between Guyana and Suriname under Part XV of the LOS Convention. Suriname objected to the jurisdiction of the Tribunal as there was a disagreement over the terminus of the land boundary. In that case, the Tribunal side-stepped the objections of Suriname by finding that “the Tribunal’s findings have no consequence for any land boundary between the Parties” (see para. 308 of the Award). However, that approach may not always be available to a court or tribunal and it is necessary to face the question of whether or not a mixed territorial-maritime dispute can be solved under Part XV of the LOS Convention.