On November 19, 2012, the International Court of Justice (ICJ) unanimously resolved a multi-year maritime boundary dispute between Nicaragua and Colombia, establishing a single maritime boundary between the two States and elaborating on the jurisprudence relating to maritime boundary disputes. The Court’s decision was complicated by the issue of sovereignty over certain islands located about 100 to 150 nautical miles (nm) off the eastern coast of Nicaragua and about 380 nm from mainland Colombia, which islands were found to be Colombian. Colombian sovereignty over such islands in the Caribbean Sea did not, however, result in the extension of the maritime area for Colombia, as Colombia had expected and argued. Rather, the ICJ carved out a “rectangular-esque” shaped maritime area around most of Colombia’s islands and enclaved two Colombian islands in the Caribbean Sea (see Sketch-Map 11; p. 89 of the judgment) to account for Colombia maritime areas that fall within what would have been Nicaraguan waters absent Colombian sovereignty over the islands.
The ICJ’s opinion in Territorial and Maritime Dispute between Nicaragua and Colombia materially expands Nicaraguan maritime territory in the Caribbean Sea. This newly established maritime boundary may affect those with oil and gas or fisheries interests in the Caribbean Sea, considering that the countries had been using the 82nd meridian as the de facto maritime boundary. Reacting to the Court’s decision, Colombia’s president Juan Manuel Santos declared that the ICJ made a “serious error in judgment” in its decision to hand over large chunks of sea around the island of San Andrés to Nicaragua, and almost immediately after the Court rendered its decision, President Santos threatened to ignore the ICJ’s verdict. However, there is very limited recourse for Colombia given the formal, legal finality of the ICJ’s decision.
1. Implications of the ICJ’s Decisions
The Court’s decision reiterates the key modern principles of international maritime delimitation, but also formally recognizes that maritime delimitation is not a science. Instead, specific facts surrounding each maritime delimitation case will affect the application of the established law, often substantially. Given a maritime boundary dispute, the principles, methods, and techniques of delimitation are predictable, but predicting the maritime boundary an adjudicative body would draw is challenging given the different ways in which they have been drawn. Additionally, once the ICJ has delivered its decision on a maritime dispute by drawing a maritime boundary, a State’s only recourse to an unfavorable judgment is to reach an agreement with the other States involved and enter into a maritime treaty.
2. Maritime Boundary between Nicaragua and Colombia
Based on evidence that Colombia has sovereignty over the islands to the east of Nicaragua, both Nicaragua and Colombia had overlapping maritime claims in the Caribbean Sea. The Colombian islands intercept Nicaragua’s maritime area due to their location well within 200 nm from Nicaragua’s coast. In such a case, the ICJ had to balance competing considerations of providing both mainland Nicaragua and the Colombian islands with their maritime entitlements under customary international law, codified in the UN Convention on the Law of the Sea (UNCLOS). The ICJ determined a single maritime boundary — purportedly achieving an equitable result for both States — by applying a five-step process.
First, the ICJ defined the relevant coasts of the two States. Nicaragua’s coast was defined as its entire coast with the exception of a short stretch, which faces south and thus does not project into the area of the overlapping claims. As for Colombia, the ICJ confined the relevant coast to the coasts of the islands over which Colombia has sovereignty and ignored the mainland coast of Colombia since it “does not generate any entitlement in that area.” The relevant coasts are shown in Sketch-Map No. 6 (see p. 58 of the judgment). The Court calculated the ratio of the relevant Nicaraguan and Colombian coasts (1:8.2 in favor of Nicaragua) to verify, in the final step, that the ICJ’s newly established maritime boundary was not disproportionate, as compared to the relevant maritime area.
Second, the ICJ defined the relevant maritime area, which comprises that part of the maritime space in which the potential entitlements of the parties overlap and which was subject to division based on the maritime boundary. The Court excluded those areas that would affect the rights of third-party States and areas over which neither Nicaragua nor Colombia had an overlapping maritime claim. The ICJ determined that the relevant area extends from the Nicaraguan coast to a line in the east 200 nm from Nicaragua’s baselines (see Sketch-Map No. 7; p. 64 of the judgment). In doing so, the ICJ rejected Colombia’s argument that the relevant area stops at the western coasts of the Colombian islands, and found that Nicaragua’s coast projects “a potential maritime entitlement across the sea-bed and water column for 200 nautical miles….[which extends] to the east of the Colombia islands.” The Court, thus, indicated that the presence of another State’s island/s in the maritime area of a mainland State cannot completely deprive the latter of most of its maritime area.
Third, the ICJ reiterated that standard method of delimitation involved construction of a provisional median line between the coasts of Nicaragua’s mainland and Colombia’s islands, which is calculated using each coast’s base points. The Court decided that Nicaragua’s base points are located at the cays and islands off the Nicaraguan coast because these features form a part of the coast itself. The base points of Colombia were held to be located at the major islands, like Santa Catalina/Provedencia and San Andrés islands; smaller islands were not included in the base points for Colombia, for they were very small maritime features that would “distort the relevant geography.” The Court then constructed the provisional median line (see Sketch-Map No. 8; p. 76 of the judgment).
Fourth, the ICJ considered factors necessitating adjustment or shifting of the provisional median line in order to achieve an equitable result and extended the boundary line eastward, out to the 200 nm line, to carve the maritime area for Colombia (see Sketch-Map No. 11; p. 89 of the judgment). As it has done in previous cases, the ICJ considered the following factors that were applicable to the specific situation in this case:
- Disparity in the Lengths of the Relevant Coasts: The disparity between the Nicaraguan and Colombian coasts (1:8.2 in favor of Nicaragua) is a substantial disparity that requires an adjustment of the provisional line.
- Geography and Cut-off Effect: Because the delimitation line should allow coasts to produce their effects in terms of maritime entitlements in a reasonable and mutually balanced way, the cut-off effect of the provisional median line is a relevant circumstance for purposes of adjusting the provisional line.
Noting that there are various techniques that allow for relevant circumstances to be considered in order to achieve an equitable result, the Court used an infrequent approach of weighting to construct the maritime boundary dividing the maritime area between Colombia and Nicaragua: Colombian base point was weighted as one, and Nicaraguan base poinds weighted as three, thereby using a 3:1 ratio between Nicaragua and Colombian base points, respectively, to construct the boundary. The Court then defined the points on the boundary (known as an “equiratio” line) by this constant ratio of its distance from the nearest point of the baselines (see Sketch-Maps Nos. 8 and 9; pp. 76 and 86 of the judgment). It was this equiratio line whose endpoints in the North and South were extended east to the 200 nm line.
Lastly, the ICJ tested the result achieved by the boundary depicted in Sketch-Map No. 11 (see p. 89 of the judgment) to determine whether significant disproportionality would require further adjustments of the provisional median line. At this stage, the ICJ compares the ratio of the relevant coasts (from step 1) and the ratio of the relevant maritime area awarded to each State, based on the calculation of the relevant maritime area (from step 2). The Court concluded that the result of its maritime boundary was not significantly disproportionate even where the divided relevant area had a ratio of about 1:3.44 (Colombia:Nicaragua), while the ratio of the relevant coasts was about 1:8.2.
3. Effect of the ICJ Decision and Obligations of Nicaragua and Colombia
The judgment in this case is final and binding as to Nicaragua and Colombia, and without possibility of appeal. While it is possible for a party to request revision of the Court’s judgment, the ICJ is unlikely to admit the matter to revise its decision absent a compelling new fact that would be decisive as to the maritime boundary issue. While Colombia, for its part, has responded to this adverse judgment by withdrawing from the Pact of Bogotá—an agreement signed in its capital in 1948 under which Latin American countries have agreed to use the ICJ to settle boundary disputes—its only recourse to avoid the effect of the judgment is to reach an agreement with Nicaragua. Entering into a maritime treaty with Nicaragua under which Nicaragua would negotiate and cede the expanded maritime area it has won, however, is unlikely.