Flashpoints | Security | Southeast Asia

The 2016 South China Sea Arbitration Award at 10: Its Lasting Significance

The award did not settle maritime disputes in the region. But it did fundamentally clarify the interpretation of maritime entitlements under UNCLOS – and forced countries to clarify their claims in turn.

A view of Scarborough Shoal taken during by the International Space Station (ISS) on Oct. 24, 2015.

Although the 1982 United Nations Convention on the Law of the Sea (UNCLOS) established the fundamental legal framework governing maritime rights and jurisdiction, the absence of judicial interpretation on key issues such as historical rights, the legal status of maritime features, and the basis for generating maritime entitlements allowed competing legal narratives to persist and evolve in different directions.

One of the most important legacies of the 2016 South China Sea Arbitral Award was not the final settlement of maritime disputes in the region. Rather, it fundamentally clarified the interpretation of maritime entitlements under UNCLOS. In other words, the award has altered the manner in which states formulate and justify their maritime claims under UNCLOS. Thus, the overlapping and complex maritime claims in the South China Sea have begun to be slowly reframed in a more transparent and clearer legal framework.

Reinterpreting Maritime Entitlements in the South China Sea

In the South China Sea before 2016, the disputes were not only about competing sovereignty claims and overlapping maritime zones but also about different interpretations of the legal basis for establishing and justifying maritime entitlements. 

Taking advantage of these ambiguities, China adopted a strategy of calculated ambiguity through its “nine-dash line” claim, citing historical evidence to justify its claims in the South China Sea. Beijing pointed to alleged “historic rights” over waters that it asserted had long been used and exploited by Chinese nationals. Nevertheless, the ambiguous legal meaning and vague geographical scope of the “nine-dash line” created large gray areas in the disputes between China and other claimant states.

The 2016 Arbitral Award clarified these ambiguities considerably. Rather than addressing questions of territorial sovereignty or maritime delimitation, the tribunal concentrated on clarifying a number of basic legal questions under UNCLOS. In particular, it made influential interpretations on two basic issues.

First, regarding historic rights, the tribunal ruled that the exception concerning “historic title” under Article 298 of UNCLOS could not be used to justify the ill-defined “historic rights” claimed by China. Furthermore, the tribunal confirmed in paragraph 246 of the award that, for states parties to UNCLOS, any pre-existing historic rights that are incompatible with the convention are superseded by the maritime rights established under UNCLOS.

What this meant was that historical arguments could not, by themselves, support an independent legal claim to maritime entitlements beyond those permitted by the convention. The tribunal therefore concluded that China’s claims to historic rights had no legal basis because they were incompatible with the regime of maritime rights and interests established in UNCLOS. 

Second, the award provided a significant clarification of the legal status of maritime features under Article 121(3) of UNCLOS. Before the award, although the convention distinguished between islands and rocks, the criteria for determining whether a feature could generate an exclusive economic zone (EEZ) and continental shelf had not been fully developed in international practice. This was especially the case in the South China Sea.

For the first time, Article 121 and Clause 3 of Article 121 were interpreted in a detailed manner by an international tribunal. The tribunal held that only features capable of sustaining “human habitation” or “an economic life of their own” are entitled to an EEZ and continental shelf under Article 121(3). Features that fail to meet this threshold are entitled only to a territorial sea of up to 12 nautical miles.

The tribunal’s interpretation was based on the natural capacity of a feature to sustain human habitation and economic life, rather than the presence of military personnel or economic activities dependent on external support. Although this interpretation remains the subject of academic debate, the 2016 Award nevertheless provided a significantly more concrete interpretative framework for Article 121(3) than had previously existed.

Why the Arbitral Award Is Not a Dead Letter

Despite Beijing’s continued adherence to its “Four No’s” policy toward the 2016 Award (no acceptance, no participation, no recognition, and no implementing), the ruling’s legal significance and practical impact have never been diminished. On the contrary, the award has become a framework reshaping the broader landscape of disputes in the South China Sea. Over the past decade, coastal states in the region, including China, have increasingly been compelled to adjust and reinterpret their maritime claims in light of the legal standards established by the tribunal.

Although China continues to characterize the award as “null........

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