On 13 July 2023, The International Court of Justice (ICJ) delivered its judgement on the merit of the case concerning Question of the Delimitation of the Continental Shelf between Nicaragua and Columbia beyond 200 nautical miles from the Nicaraguan Coast. The Court found that Nicaragua is not entitled to an extended continental shelf within 200 nautical miles from the baseline of Colombia's mainland coast. This case began in the year 2013 when an application was filed by Nicaragua against Colombia for the interference of the International Court of Justice (ICJ) for determining the continental shelf between the two countries.

A continental shelf is a land mass or the area submerged in the water and as per the International law concerns a continental shelf extends from the territorial waters of a country to 200 nautical miles of area. In this case Nicaragua wanted the ICJ to determine this continental shelf between two countries. It is an important part of any country because of the marine resources and Maritime resources are rich in biodiversity and scenic beauty impacting countries marine tourism along with natural resources such as hydrocarbon.

Due to such important of continental shelf it becomes an important aspect for International peace and harmony among the countries, so it is necessary to establish marine boundaries among the countries which share these marine borders and one of these prominent examples of marine borders conflict is of Nicaragua v. Colombia.

Background of the Dispute;
The countries Nicaragua and Colombia have shared a common history of marine disputes dated back in the years of 1920's. In the year 1928 Colombia and Nicaragua signed a treaty according to which Colombia recognised the sovereignty of Nicaragua over the mosquito coast and corn islands while Nicaragua recognised Colombia sovereignty over the islands of San Andres, Providencia and Santa Catalina the treaty named was barcenas esguerra treaty which was signed on 24 march 1928.

The conflict between Nicaragua and Colombia emerged to new heights when Nicaragua in the year 2001 brought a case against Colombia in the ICJ for seeking territory over Caribbean Sea and in the year 2012 Court gave Nicaragua few several thousand square kilometres over the Caribbean Sea. In response to the 2012 Judgment, Nicaragua brought a second lawsuit against Colombia in 2013. In the portions of the continental shelf that relate to each of them beyond the parameters established by the Court in its judgment of November 19, 2012, Nicaragua asked the Court to precisely map out the maritime boundary between Colombia and Nicaragua.

Stated differently, Nicaragua asked the Court to define the maritime limit that extends beyond 200 nautical miles from its own shore. Even though this case is still proceeding, Colombia's preliminary objections have already been dismissed by the Court, which issued two significant conclusions in its judgment on March 17, 2016. First, it concluded that, with regard to the delineation of the continental shelf beyond 200 nm, the 2012 judgment was not res judicata. Second, it decided that, in cases like Nicaragua's continental shelf beyond 200 nm, maritime boundaries can be established even in the absence of established outer limits to the continental shelf. The conflict must move forward to the merits phase.

Questions of Law:
What was UNCLOS's relevance? : The UNCLOS contains a large codification of international law of the sea. Not every coastline state is a party to UNCLOS, though. Because Colombia is not an a party to the UNCLOS, the parties in this case were urged to base their arguments on customary international law.

What is customary international law? : Customary international law is like the unwritten rules everyone follows in a community. It's based on what countries do repeatedly and agree on over time. These agreed-upon practices become the standard, even without a formal agreement, and are respected as binding rules in the international community.

Why is the 200 Nautical mile delimitation relevant? : The 200 nautical mile delimitation, established under the United Nations Convention on the Law of the Sea (UNCLOS), is crucial because it determines a nation's exclusive economic zone (EEZ), granting rights over natural resources within that zone. It helps countries manage and exploit marine resources while respecting the sovereignty and rights of neighboring states, thereby preventing conflicts and promoting cooperation in maritime activities.

What is the Continental Shelf? : According to UNCLOS Article 76, the continental shelf is the seabed and subsoil of the submarine areas that extend beyond the territorial sea of a coastal state in the natural extension of that state's land area to the outer edge of the continental margin, or up to 200 nautical miles beyond the baselines from which the territorial sea's breadth is measured in cases where the outer edge of the margin does not extend that far. Put differently, a State's right to a continental shelf under customary international law—which is embodied in Article 76 of the UNCLOS—is established by two distinct criteria: distance, which is measured within 200 nautical miles of its baselines, and the "natural prolongation" criterion, which is beyond 200 miles, but where specific scientific and technical standards can be used to determine the continental shelf's outer bounds.

International Court of Justice view on this case:
After that, the Court discussed issues pertaining to the regime that oversees the outer continental shelf. The Court raised three issues. First, in accordance with customary international law, there are different criteria for determining who is entitled to a continental shelf within and beyond 200 nautical miles. An outer continental shelf's eligibility is determined by whether the shelf is a natural extension of a state's territory, whereas eligibility for a continental shelf within 200 miles is exclusively based on distance from the coast.

Second, "to avoid undue encroachment on the sea-bed and ocean floor and the subsoil thereof, beyond the limits of national jurisdiction" was the stated goal of the substantive and procedural requirements under the United Nations Convention on the Law of the Sea (UNCLOS) for establishing an outer continental shelf, regarded as "the shared legacy of humankind." Therefore, it is reasonable to suppose that states believed an outer continental shelf could only reach regions that were not under the control of another state.

The Court's third point was arguably the most important and controversial. The Commission on the Limits of the Continental Shelf (CLCS), which issues "final and binding" recommendations to states claiming an outer continental shelf, received submissions from "the vast majority" of UNCLOS states parties, according to the Court.

These states opted not to assert their right to a continental shelf within 200 nautical miles of the coasts of other states. Even though this conduct may have been partially driven by factors other than a sense of legal obligation, the Court believed that it "is indicative of opinio juris." Furthermore, no state not party to UNCLOS was known to the Court to be asserting that its outer continental shelf infringed upon another state's 200 nautical mile maritime entitlement.

Conclusion:
Even though it is said that ICJ's decisions are not binding on the parties but still in this case of Nicaragua v. Colombia ICJ played a vital role in determining the question of facts and the conclusion driven by the question of laws that were discussed in matter and in the end the ICJ safeguarded the sovereignty of Colombia over the claims of Nicaragua.

The Court decided that Nicaragua wasn't entitled to the continental shelf beyond 200 Nautical miles and this judgment is important because court in this case for the first time has given a decision over the issue of whether the outer continental shelf can overlap with other country's continental shelf and exclusive economic zone (EEZ) and this decision can be said as an ending to decades long maritime dispute between the two nations.

References:

• https://www.engage.hoganlovells.com/knowledgeservices/news/international-court-of-justice-clarifies-rules-on-delimitation-of-maritime-boundaries-with-significant-impact
• https://cil.nus.edu.sg/blogs/the-icjs-2023-judgment-in-nicaragua-v-colombia-a-new-chapter-in-the-identification-of-customary-international-law/
• https://www.icj-cij.org/case/124
• https://www.geopoliticalmonitor.com/icj-to-rule-on-colombia-nicaragua-maritime-dispute/