Some Observations on the U.S. Announced Extended Continental Shelf Outer Limits

On December 19, 2023, the United States Department of State announced the outer limits of its continental shelf in areas beyond 200 nautical miles from the territorial sea baselines, or extended continental shelf (ECS), in various coastal regions including the Arctic, Atlantic (east coast), Bering Sea, Pacific (west coast), Mariana Islands, and two areas in the Gulf of Mexico. The ECS Task Force, chaired by the Department of State, oversees the delineation of these outer limits. The US Geological Survey (USGS) is responsible for collecting, processing, and interpreting seismic and geologic data, while the National Oceanic and Atmospheric Administration (NOAA) handles bathymetric data collection, processing, and analysis. This has sparked debates regarding whether the United States can bypass the Commission on the Limits of the Continental Shelf (CLCS) to proceed with the delineation of its continental shelf limits.

What legal issues are involved?

Articles 76 through 85 in Part VI of the United Nations Convention on the Law of the Sea (UNCLOS) are dedicated to provisions concerning the continental shelf, including the determination and delineation of the outer limits of the extended continental shelf beyond 200 nautical miles, and other rights of States over the continental shelf.

UNCLOS establishes two distinct criteria for continental shelf entitlement: either a distance of 200 nautical miles or the outer edge of the continental margin. When entitlement is based on the latter criterion, the coastal state must provide scientific evidence to substantiate the claim.

As one of the three institutions established under UNCLOS, the CLCS primarily serves two significant roles: evaluating the claims of a Coastal State for an area of the continental shelf beyond 200 nautical miles and, upon request, providing scientific and technical advice to the Coastal States in the preparation of their submission of the claim. UNCLOS has further stipulated that for the outer limits to be final and binding on the Coastal States, they must be determined by the Coastal State based on the CLCS’s recommendation.

The complex legal framework governing the determination of extended continental shelf boundaries underscores the crucial role of the CLCS as a credible institution tasked with evaluating the validity of such claims.

Debates on U.S. ECS announcement

A Wilson Center article argues that “the United States Executive Summary and the decades of work that support it are consistent with international law and the global rules-based order for the oceans.” Two legal issues merit discussion here. Firstly, without ratifying UNCLOS, could the United States present a submission package to the CLCS?

The U.S. Department of State stated that: “The United States has prepared a submission to the CLCS.  The Department of State will file it with the Commission when the United States joins the Law of the Sea Convention.  The United States is also open to filing its submission with the Commission as a non-Party to the Convention.” This statement suggests that the US views paragraph 8 of Article 76 as reflective of customary international law, thereby allowing it to institute a procedure before CLCS and confer binding force on its delineation.

Article 76 of UNCLOS does not explicitly address the participation of non-member states. Nevertheless, the CLCS has allowed the United States, despite not being a party to UNCLOS, to submit communications regarding submissions made by UNCLOS member states, as it did for submissions from Australia, Brazil, China,  Russia and Canada. According to the CLCS, the role of other states is limited to considering data and materials submitted by coastal states regarding the outer limits of the continental shelf beyond 200 nautical miles. The Commission would only need to consider communications from states other than the submitting one in cases of disputes between states with opposite or adjacent coasts, or in other instances of unresolved land or maritime disputes. For example, the United States sent a letter to the CLCS regarding Brazil’s submission. However, the CLCS concluded that since the United States had no delimitation dispute with Brazil, its letter should not be taken into consideration. [1] The United States further appealed the CLCS’s decision.

It remains to be seen if and how the CLCS will react to a non-party submission. Despite ongoing efforts to gather scientific evidence to support future claims along its Atlantic, Gulf, and Alaskan coastlines, the United States’ failure to ratify UNCLOS may bar its involvement in the CLCS proceedings.

The second legal issue pertains to whether the United States can determine the limits of its extended continental shelf under customary international law without CLCS involvement. Some may argue that continental shelf rights are inherent for all coastal states, regardless of their status as a party to UNCLOS or their proclamation of those rights. However, due to the absence of general State practice and opinio juris, paragraph 8 of Article 76 does not appear to establish customary international law. Consequently, it is difficult to contend that non-parties to UNCLOS have access to CLCS proceedings. Even if the rights to a continental shelf are inherently recognized under international customary law, bypassing the CLCS, the US undermines the established international process, thereby casting doubt on the credibility and acceptability of its extended continental shelf limits.

The US may argue that its announcement aligns with customary international law, even without ratifying UNCLOS, to the extent that it informs the global community about the extent of its continental shelf—”data collected as part of the U.S. ECS Project have been made available to the public as quickly as possible after collection and processing.” However, in the absence of a CLCS submission, other states are tasked with assessing the credibility of the United States’ claimed ECS. Unlike situations where the outer limits are determined by distance, evaluating the credibility of limits based on scientific criteria presents challenges for other states that may lack the necessary resources.  Furthermore, it’s crucial to take into account the significant backlog of submissions, which stood at 93 submissions as of 2022. These submissions are reviewed in the order they are received. Therefore, even if the United States were to submit a claim, the review process could potentially span decades. Moreover, it’s difficult to imagine how the CLCS, a treaty body explicitly established under UNCLOS, could consider the submission of a non-party.

Implication for geopolitics and ocean governance

There have been discussions within Russia regarding the potential withdrawal from UNCLOS. Some argue that ratifying and implementing UNCLOS in the Arctic has needlessly restricted the country’s flexibility. Proponents however highlight the strategic success of the Soviet Union within UNCLOS, “which secured unprecedented rights in ice-covered areas and established procedures for recognizing sovereign rights over significant continental shelf areas.”

Russia was at the forefront of submitting claims under Article 76 to the CLCS. Its initial submission in 2001 resulted in a recommendation from the CLCS in 2002. Subsequently, in 2013, Russia submitted a partially revised submission concerning the Okhotsk Sea, leading to the adoption of the recommendation by the CLCS in 2014. In 2015, Russia submitted a partially revised submission to the CLCS regarding the Arctic Ocean and received the recommendation in 2023. Among the other three Arctic littoral states—Denmark, Norway and Canada, excluding the United States—all have submitted claims to the CLCS within the designated deadline. As of 2023, only Russia and Norway have received recommendations from the CLCS. Consequently, Russia has notably benefited from the outer continental shelf regime, which is often regarded as the primary incentive of joining UNCLOS. However, the recent decision by the United States to declare extended continental shelf limits without involving the CLCS appears to convey a message—participation in UNCLOS may be perceived as burdensome and unnecessary.

The United States affirmed its adherence to the provisions of UNCLOS, excluding those found in Part XI on the ‘AREA’, as customary international law. In a more recent development, on April 29, 2022, the US Legal Advisor spoke at the UN General Assembly, reiterating the US’s support for UNCLOS and its ongoing recognition of much of the Convention as reflective of customary international law.

Both Russia and China, as member states of UNCLOS, often challenge the United States for selectively interpreting and stretching arguments, which disrupt the globally accepted order. Conversely, the United States consistently criticizes China’s South China Sea policy, accusing it of not adhering to UNCLOS. Despite numerous legal issues surrounding the South China Sea, such as the island regime, the primary concern is the relationship between UNCLOS as a treaty law and historic rights as customary international law. The United States stresses the importance of adhering to UNCLOS as the primary legal framework and questions China’s maritime claims in the South China Sea based on the U-shaped Line using other principles of international law.

The recent announcement by the US regarding its continental shelf limits, grounded in customary international law, has the potential to create confusion within the international community regarding its stance on UNCLOS and other customary international laws. Determining whether a provision of UNCLOS has the status of customary international law should not be arbitrarily based on the national interests of a State but should depend on whether it fulfills the constituent elements of customary international law. A unified international response urging the United States to adhere to established norms would underscore the significance of institutions like the CLCS in maintaining order in the complex domain of ocean governance.

The United States’ ECS action indicates its keen interest in delineating the boundaries of the extended continental shelf across various regions, notably including the Arctic. In the Arctic context, interests of international stakeholders extend beyond purely geo-economic factors to encompass broader security considerations. In the past two years, there’s been a severe shift in Arctic geopolitics. Russia views the increasing presence of NATO forces near its borders as a threat and has pledged to reinforce its military capabilities in its northern and western territory to counter NATO’s expansion. Furthermore, Russia faces significant obstacles in its Arctic economic pursuits due to U.S.-led economic sanctions following the Ukraine crisis. These developments illuminate the geopolitical dynamics between Russia and the United States.

The United States’ ratification of UNCLOS may offer a resolution to the legal ambiguities and alleviate criticisms regarding its selective interpretation of relevant provisions. Similarly, advocates argue that U.S. membership in UNCLOS would facilitate access to deep-sea mining, bolster critical mineral supply security, expand into deep-sea markets, and enhance national security. However, the prospect of U.S. ratification appears distant due to historical opposition to Part XI of UNCLOS on regulations of seabed resources in the Area, particularly regarding technology transfer rights to the international seabed mining regime. The uncertainty surrounding U.S. presidential elections and the lengthy ratification process further delay any potential accession.

[1] Statement by the Chairman of the CLCS on the progress of work in the Commission-14^th Sess., Doc, CLCS/42, para. 17.