Conflict within the South China Sea (SCS) – most notably, the South China Sea Arbitration – may be one of the most politically charged challenges to maritime boundaries in the modern era. At the heart of this dispute is the tension between China’s historical title over ninety percent of these waters, as dictated by its nine-dash line, and maritime entitlements laid out in the United Nations Convention on the Law of the Sea (UNCLOS).

The UNCLOS is an international, non-legally binding agreement designed to settle all issues relating to the law of the sea. Even before the signing of UNCLOS in 1982, maritime delimitation, which involves the artificial drawing of ocean boundaries, was an issue. At the time, most signatories agreed to the concept of an Exclusive Economic Zone (EEZ), a zone extending no more than 200 nautical miles from a nation’s territorial sea baseline that gives coastal nations jurisdiction over the ocean’s natural resources. Yet, there has been a lack of consensus regarding the administrative power of EEZs. This vagueness is especially true of the continental shelf or the underwater border of a continent and other features that distort the land-sea divide.

The South China Sea Tribunal ruled that artificial installations built atop underwater structures naturally existing within the SCS do not extend a nation’s EEZ. However, this ruling fails to truly resolve issues of maritime boundaries and perpetuates the conflict between human efforts to define and control the sea integrated into international law and the physical geography of the ocean.

Why is the South China Sea so important?

The SCS is a semi-enclosed body of water that bridges China, Taiwan, Brunei, Cambodia, Indonesia, Malaysia, Myanmar, Vietnam, the Philippines, Malaysia, and arguably, Singapore. The ocean region features a constellation of islands, reefs, rocks, and other marine features – several of which have become the object of disputes between nations seeking to boost their economic and military welfare.

Since time immemorial, the SCS has been a fertile fishing ground for local fishers and a vital route for trade and transportation. This “Silk Road on the Sea” may be the most enduring maritime trade route in history and has only grown in importance due to advances in deep-sea mining technologies. These advances have enabled previously untapped resources, such as oil and natural gas in its seabed and subsoil, to be extracted and consumed in the name of development and security.

If any one nation were to gain near-exclusive control over these disputed waters, this would threaten the relative peace the region has enjoyed up until the late twentieth century. For now, China appears to be the most likely candidate to occupy this role. Though all nations involved in the SCS disputes have engaged in land reclamation efforts, none have come close to the scale of China’s island-building initiatives. China has also sought to stake its historical claim to the region by negotiating with neighbouring states and pressuring challengers through economic coercion.

Given the widespread perception among Western countries and their allies regarding China’s desire to dominate, rather than peacefully rise in prominence as a leader on the world stage, this has led to a host of domestic and international security concerns.

A Brief History of the SCS Arbitration

On January 22, 2013, the Philippines initiated the South China Sea Arbitration to settle its disputes with China over maritime jurisdiction in the SCS. Despite China’s refusal to accept or participate in compulsory arbitration, the proceedings continued. The Tribunal later ruled China’s encroachment into the Philippines’s EEZ violated the UNCLOS.

In China’s eyes, the SCS disputes are primarily maritime delimitation issues that fall outside of the UNCLOS’s scope. China’s argument has relied on its alleged historical title to the SCS islands and their adjacent waters. A major source of supporting evidence is the existence of the nine-dash line, a maritime boundary drawn between China and its neighbouring states within the SCS in the 1930s. To demonstrate its alleged historical rights and title, China must exhibit the time-honoured acceptance of this ancient maritime border within the international community. To do so, China points to its continuous and peaceful sovereignty over the islands and its territorial waters dating back to over 2,000 years ago, along with its status as the first to discover, name, explore, and exploit the island’s resources.

The Philippines, on the other hand, argued China has unlawfully interfered with its territorial sovereignty. One example of this is China’s artificial installations atop low-lying topographies within the nine-dash line, which China has used in an attempt to expand its EEZ under international law. Under the UNCLOS, islands located within the maritime zones of a country can extend the country’s EEZ up to 200 nautical miles from the island’s continental shelf. This is not true of low-lying topographies. Rocks, which are incapable of sustaining human life or an economy of their own, are only entitled to twelve meters of the territorial sea. Low tide elevations that become fully submerged at high tide are not granted any maritime zones. Furthermore, as pointed out by the Philippines, previous tribunals have ruled that the UNCLOS should take precedence when discrepancies between ancient and modern maritime boundaries arise—although historical rights were granted under certain circumstances.

Changing Tides

Whereas the land is a relatively fixed space, the sea is constantly in motion—from the waves to the sand and sediment that line the ocean floor. The sea also sculpts geological features within its waters through erosion, which whittles away at ancient marine landscapes and gives birth to new sands. These changes have complicated matters of maritime delimitation because without stable geographies to outline countries’ territorial waters, the resources, and rights guaranteed under the UNCLOS are easily muddled.

Examples of the erosive relationship between the land and sea are abundant in the historical and geological literature. Many of the reefs and atolls—a ring-shaped coral reef, island, or series of islets—within the SCS may have even once been fully-fledged islands several millennia ago. As sea levels rise, threatening to erode and submerge low-lying topographies within the SCS, artificial installments may be required for nations to maintain their territorial sovereignty.

If permitted by international courts, artificial installments could conflict with previous rulings on the maritime zones of artificial islands and may require alterations to the UNCLOS’s notion of EEZs. If these installments are prohibited, rising sea levels may convert features into rocks or low-tide elevations with little or no maritime jurisdiction.

Although these futuristic scenarios seem far-fetched, coastal erosion is a major issue within the SCS and its surrounding areas. Since China’s reclamation of Woody Island, a maritime feature within the SCS, the nation has worked to fortify the island’s coast against erosion. Local authorities plan to brace over 2,000 meters of coastline and implement other prevention measures, demonstrating China’s intention to maintain a permanent presence in the SCS.

Suppose the unclear boundaries of the SCS are reworked due to climate change. In that case, this may heighten tensions within the region and call for changes to the UNCLOS’s invention of EEZs and provisions relating to artificial installments.

Edited by Pearl Zhou