Prior to the 2016 award, disputes in the South China Sea were not confined to competing sovereignty claims and overlapping maritime zones. They also reflected differing interpretations of the legal basis for establishing and justifying maritime entitlements. China took advantage of these ambiguities by invoking the Nine-Dash Line and its alleged "historic rights" over waters that it claimed had long been used and exploited by Chinese nationals. The vague legal meaning and uncertain geographical scope of the Nine-Dash Line created extensive grey areas in disputes between China and the other claimant states. The Tribunal's ruling significantly reduced these ambiguities, clarifying important legal questions relating to maritime claims, sovereignty, territorial seas and Exclusive Economic Zones (EEZs), and thereby reshaping the region's legal and strategic landscape. 

As two Vietnamese legal scholars, Cao Nguyen Khanh Huyen and Nguyen Tanh Long, have observed, "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 their view, the award altered the manner in which states formulate and justify their maritime claims under UNCLOS. Rather than attempting to resolve questions of territorial sovereignty or maritime delimitation, the Tribunal concentrated on clarifying several fundamental legal principles governing maritime entitlements under the Convention. 

In particular, the Tribunal made important interpretations on two fundamental issues. 

First, with regard to historic rights, it ruled that the exception concerning "historic title" under Article 298 of UNCLOS could not be invoked to justify the ill-defined "historic rights" claimed by China. It further confirmed, in paragraph 246 of the award, that for states party to UNCLOS, any pre-existing historic rights incompatible with the Convention are superseded by the maritime rights established under UNCLOS. Historical arguments, therefore, cannot by themselves support independent legal claims to maritime entitlements beyond those recognized by the Convention. The Tribunal consequently concluded that China's claims to historic rights had no legal basis because they were inconsistent with the legal regime established by UNCLOS. 

Rules-Based Maritime Order

Second, the award significantly clarified the legal status of maritime features under Article 121 (3) of UNCLOS. Although the Convention distinguishes between islands and rocks, the criteria for determining whether a maritime feature could generate an Exclusive Economic Zone and continental shelf had remained inadequately defined in international practice, particularly in the South China Sea. For the first time, an international tribunal interpreted Article 121 (3) in considerable detail. It held that only features capable of sustaining human habitation or an economic life of their own are entitled to an Exclusive Economic Zone and continental shelf. Features failing to meet this threshold are entitled only to a territorial sea of up to twelve nautical miles. Although this interpretation remains open to academic debate, the award nevertheless provided a much clearer legal framework for interpreting Article 121(3) than had previously existed. 

Despite China's efforts to characterize the award as "null and void" and its continued adherence to its policy of the "Four Nos"-no acceptance, no participation, no recognition and no implementation-the ruling has continued to shape the legal landscape of the South China Sea. As the Vietnamese scholars observe, "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 found themselves compelled to reinterpret and justify their maritime claims in light of the legal standards established by the Tribunal. While Beijing has continued its creeping expansion and occupation of islands, reefs and maritime features, it has simultaneously invested considerable diplomatic and legal effort in attempting to discredit the award. Yet the very evolution of China's legal arguments demonstrates the award's enduring influence. 

The Nine-Dash Line

Since 2016, China has gradually reduced its reliance on the "Nine-Dash Line" while increasingly emphasizing the "Four Shas" doctrine (Nanhai Zhudao), recasting its maritime claims in terminology more closely aligned with UNCLOS and avoiding explicit reliance on the Nine-Dash Line. Although these changes do not represent acceptance of the Tribunal's ruling, they nevertheless suggest that Beijing has been compelled to adapt its legal arguments to the post-2016 legal environment. Ironically, even while rejecting the award politically, China has increasingly framed its maritime claims within the legal vocabulary that the award itself helped to reinforce.

Two countries that have competing claims on South China Sea, and have experienced most aggressive behaviour of China in preventing them forcefully to carry on their legitimate economic activities in their respective EEZs under UNCLOS, are Vietnam and the Philippines, whose Coast guards often clashed with China's. In accordance with the country's consistent policies on SCS, during the tenth anniversary reaffirmed its stance that maritime disputes must be resolved peacefully and in strict accordance with international law. Vietnam's Ministry of Foreign Affairs reiterated that the 1982 UNCLOS is the sole legal framework governing maritime entitlements. While Vietnam didn't formally sign on to the initial 2016 arbitration, it has consistently supported the utilization ofUNCLOS dispute mechanisms and peaceful diplomatic processes without the threat and use of force. The milestone coincided with Vietnam's historic election of its first-ever Judge, Associate Professor Dr, Gwyn Tilan, to the International Tribunal for the Law of the Sea (ITLOS) for the 2026-2035 term. International experts view the appointment as a significant milestone, cementing Vietnam's dedication to global maritime governance and the rule oflaw. 

The 2016 arbitral award embodies a dual legacy from the Filipino perspective, as the award was given in response to its application to the Tribunal for adjudication on their disputes with China on the Scarborough Shoal: it stands as an immovable anchor for Philippine national identity and international law, even as Beijing wages a multifront campaign to erode its legitimacy both in legal forums and on the water. At the Philippine Department of Foreign Affairs-led July commemorative conference in Pasay City, Philippine officials underscored how the award has been woven into domestic law and daily life. Foreign Affairs Secretary Tess Lazaro described the ruling as a "lighthouse." : "A lighthouse does not block the winds, it does not command the tides. It stands immovable upon bed rock, casting a steady. Piercing beam to warn of hazards and guide all ships, beautifully described by Filipino Foreign Secretary Tes Lazaro Predictably, the most unequivocal support for the Tribunal Award on its tenth anniversary came from the Western countries.

Freedom Of Navigation 

The text of the following statement was released by the government of the United States of America, Australia, Canada, Estonia, Italy, Germany, Latvia, Lithuania, Japan, New Zealand, the Republic of the Philippines, Romania, Slovenia and the United Kingdom: "We reaffirm our unwavering commitment to maintaining a free and open Indo-Pacific that is peaceful, stable, and rules-based, anchored in international law, and commemorate the 10th anniversary of the July 12, 2016, Arbitral Tribunal's landmark and unanimous decision on the South China Sea constituted under Annex VII of UNCLOS. We reaffirm that maritime disputes must be resolved peacefully and in accordance with UNCLOS. We reaffirm that the Award rendered ten years ago by the Arbitral Tribunal. We reaffirm the Arbitral Tribunal's decision that there is no legal basis for China's expansive maritime claims in the South China Sea, including those based on "historic rights". We underscore the importance of upholding freedom of navigation and overflight, as well as other internationally lawful uses of the sea, as reflected in UNCLOS." It also reaffirmed their strong opposition to any destabilizing or unilateral actions including by force or coercion that threaten peace and stability in the region. It further urged the parties to abide by the 2016 Award and resolve disputes peacefully through dialogue and other lawful mechanisms in accordance with international law, highlighting their steadfast support for a free and open Indo-Pacific and reiterate our commitment to promoting our shared vision with ASEAN of the South China Sea as a sea of peace, stability, cooperation, and prosperity driven by vibrant lawful commerce. 

India reiterated its support for a rule-based order in the SCS, emphasising that the 2016 Arbitral tribunal's ruling serves as a foundation for resolving competing territorial claims. It reaffirmed its stance that maritime disputes must be resolved peacefully in accordance with the UNCLOS. India's position underscores the principle of freedom of navigation, overflight, and lawful commerce. 

Despite the overall international support for the ruling, its impact on China's behaviour and practices in regard to its expansive claim on SCS and its readiness to use force to occupy the islands and features would not be very different, as evident from its current military, lawfare and diplomatic offensives that it takes resort to settle all its territorial claims. As the other claimant states on SCS are much weaker and has less leverage vis-a-vis China due to economic over-dependence on Beijing, the other and parallel option, the disputant countries are using is to create a 'Code of Conduct' to diffuse tension on the issue over last three decades, but have not succeeded in reaching a conclusion. The 2025 agreement between the Association of Southeast Asian Nations (Asean) and China on a Single Draft Code of Conduct (COC) Negotiating Text marked a significant milestone in a complex and protracted diplomatic journey spanning over two decades. This development not only reflects the commitment of regional powers to foster stability in the South China Sea but also underscores the urgent need for guidelines that curb escalating tensions and prevent potential conflicts in one of the world's most strategically vital maritime regions.

The Elusive Code of Conduct

The COC negotiations began in 2003, but progress has been slow, with the completion of the first reading only achieved in 2019 and the second in 2023. This slow pace is emblematic of the challenges inherent in balancing national interests and regional security amid competing territorial claims. The 2025 document focussed on self-restraint, particularly crucial given the backdrop of China's aggressive maneuvers in the South China Sea, including the militarization of artificial islands and assertive coast guard activities. 

ASEAN and China are pushing to finalize a substantive Code of Conduct by the end of 2026, driven by monthly face-to-face technical meetings. Despite this urgency, major obstacles remain. The Philippines, as the 2026 Asean Chair, insists the CoC must be legally binding and anchored in the 2016 arbitral ruling, but China firmly opposes incorporating the award into the talks. ASEAN claimants are demanding a substantive, legally binding document based on the 1982 UNCLOS. However, China argues, Manila's push to include the 2016 arbitral ruling creates an impassable roadblock, as Beijing rejects the awards validity entirely. Persistent standoffs and encounters between Chinese and Philippine vessels complicate the diplomatic atmosphere, leading some analysts to argue that broader geopolitical maneuvering between regional claimants and external powers (like the USA) is slowing consensus.