UNCLOS and South China Sea Maritime Disputes: Legal Complexities and Interpretations


The South China Sea has long been a focal point of international concern, mired in maritime disputes that raise complex questions regarding territorial claims, freedom of navigation, and the interpretation of the United Nations Convention on the Law of the Sea (UNCLOS). This essay delves into the multifaceted challenges presented by these disputes and the role of UNCLOS, exploring the reasons for such differing interpretations.

The maritime disputes in the South China Sea are far from being localized conflicts; rather, they hold both regional and global implications, impacting the delicate balance of power and international law.[1] The South China Sea is one of the world’s most heavily trafficked waterways, with an estimated $3.4 trillion in ship-borne commerce crossing the sea each year.[2] However, transit is not the reason many companies are interested in the South China Sea, rather many are interested in the Sea’s resources, as the U.S. Energy Information Administration predicts the South China Sea holds about 11 billion barrels of oil, 190 trillion cubic feet of natural gas, and significant fish stocks, coral, and other undersea resources.[3]

UNCLOS, adopted in 1982 and enforced in 1994, is the cornerstone of these disputes.[4] It seeks to harmonize the interests of coastal states, archipelagic nations, and the broader international community.[5] Within its comprehensive framework lies the delineation of maritime zones, protection of navigational rights, conservation of marine resources, and mechanisms for peaceful dispute resolution.[6] UNCLOS is renowned for its contributions to maintaining peace on international waters, safeguarding the marine environment, and regulating activities such as fishing and navigation.[7] However, despite its widespread acceptance, interpretations of UNCLOS vary significantly, particularly in the context of the South China Sea.

The heart of the issue lies in the interpretations of UNCLOS, which have given rise to numerous complexities and debates within the South China Sea disputes. These disputes are characterized by territorial claims that often overlap, with China’s “nine-dash line” assertion conflicting with the Exclusive Economic Zone (EEZ) claims of other littoral states, including Vietnam and the Philippines.[8] The interpretation of UNCLOS provisions pertaining to freedom of navigation has become a contentious point of disagreement.[9] The United States conducts Freedom of Navigation Operations (FONOPs) in the South China Sea to challenge perceived excessive maritime claims, whereas China views these actions as an infringement on its sovereignty.[10] Beyond legal matters, the disputes are interwoven with geopolitical and strategic considerations, influencing alliances, military deployments, and the regional power dynamics, thus further complicating the situation.

Interpreting UNCLOS presents a complex task, with multiple factors contributing to the challenges in comprehending its provisions.[11] UNCLOS, a highly technical treaty, often contains inherently ambiguous provisions, a result of negotiations involving diverse nations with varying interests.[12] Adopted in 1982, the treaty lacks explicit coverage of emerging technologies and evolving environmental concerns, allowing room for diverse interpretations as these new concerns emerge.[13] Additionally, conflicting interests among coastal states, archipelagic nations, and maritime powers frequently lead to contrasting viewpoints, with historical and cultural contexts influencing interpretations.[14] Overlapping maritime claims, intertwined with territorial disputes, further compound the situation, impacting territorial claims and resource rights. Moreover, even specific legal definitions of UNCLOS terms and concepts, such as “Exclusive Economic Zones” and “innocent passage,” remain open to various interpretations, as UNCLOS does not offer precise definitions.[15] These factors collectively underscore the enduring challenge of navigating international maritime law within the intricate tapestry of UNCLOS interpretations, marked by varying interests, historical legacies, and evolving technologies.

The South China Sea’s maritime disputes, rooted in territorial claims, freedom of navigation, and UNCLOS interpretations, present a multifaceted challenge with significant regional and global implications. Although UNCLOS is widely accepted, differing interpretations persist, leading to legal uncertainty, tensions, and geopolitical consequences. Addressing these issues necessitates diplomacy, legal expertise, and adherence to the treaty’s principles. The difficulties in UNCLOS interpretation underscore the importance of comprehensively exploring its implications to navigate the complexities of international maritime laws. Resolving these challenges is essential for promoting peace, stability, and the rule of law in the South China Sea.

[1] What is the South China Sea dispute?, BBC News, Jun. 13, 2011, https://www.bbc.com/news/world-asia-pacific-13748349 (last visited Oct 20, 2023).

[2] Ben Dolven, Caitlin Campbell, Ronald O’Rourke, China Primer: South China Sea Disputes, Congressional Research Service, Aug. 21, 2023, https://crsreports.congress.gov/product/pdf/IF/IF10607 (last visited Oct 20, 2023).

[3] Id. 

[4] U. S. Naval Institute Staff, Report to Congress on the U.N. Law of the Sea Convention, USNI News (Oct. 6, 2023), https://news.usni.org/2023/10/06/report-to-congress-on-the-u-n-law-of-the-sea-convention (last visited Oct 20, 2023).

[5] Id.

[6] See id. 

[7] See id. 

[8] Cliff Harvey Venzon, China’s Fresh Map Claims Over Taiwan, Disputed Sea Stir Protests, Bloomberg, https://www.bloomberg.com/news/articles/2023-09-01/china-s-fresh-map-claims-over-taiwan-disputed-sea-stir-protests#xj4y7vzkg (last visited Oct 21, 2023).

[9] See id. 

[10] Eleanor Freund, Freedom of Navigation in the South China Sea: A Practical Guide, Belfer Center for Science and International Affairs, https://www.belfercenter.org/publication/freedom-navigation-south-china-sea-practical-guide (last visited Oct 22, 2023).

[11] Dr Amy Creese, et al., UNCLOS: The Law of the Sea in the 21st Century, 2nd Report House of Lords: International Relations and Defence Committee (2021-2022), https://committees.parliament.uk/publications/9005/documents/159002/default/.

[12] Id.

[13] U. S. Naval Institute Staff, supra note 4.

[14] See id.

[15] UN General Assembly, Convention on the Law of the Sea, § 3(A), Art. 35-36, Art. 63, Dec. 10, 1982, https://www.refworld.org/docid/3dd8fd1b4.html.