Anchoring Peace: The Significance of a Code of Conduct in the South China Sea

The South China Sea (SCS), including part of the West Philippine Sea (WPS), is one of the most contested maritime regions in the world. It is rich in resources, vital for global trade, and home to diverse ecosystems. Yet, competing claims, artificial island construction, and militarization have turned it into a flashpoint for tension and potential conflict.¹

Environmental problems such as overfishing, pollution, and reclamation add further strain, undermining obligations under UNCLOS to protect the marine environment.² At the same time, the SCS carries about one‑third of global shipping and critical energy supplies to East Asia.³

These realities make a binding Code of Conduct (CoC) urgent.

The SCS and the WPS

The SCS is a semi‑enclosed sea bordered by China and Taiwan in the north, the Philippines in the east, and Vietnam, Malaysia, Singapore, Indonesia, and Brunei in the west and south. It contains features such as the Spratlys, Paracels, Macclesfield Bank, and Pratas Island.

The WPS refers to Philippine maritime zones on the western side of the archipelago, including the Luzon Sea, the territorial seas of Bajo de Masinloc (Scarborough Shoal), and the maritime features of the Kalayaan Island Group.⁴

Maritime Challenges in the SCS

Six nations claim parts of the SCS: China, Taiwan, Vietnam, the Philippines, Malaysia, and Brunei. Disputes involve sovereignty over islands and rights to adjacent waters and seabeds. Since UNCLOS entered into force in 1994, contests expanded to EEZs and continental shelves, especially over fisheries and petroleum resources.⁵

Over the past several years, certain claimant nations, mostly China, have been increasing assertions in the SCS, raising concerns that affect the freedom of navigation and regional stability. Among their activities are:

• Land reclamation and militarization of reefs into artificial islands.
• Harassment of fishing and exploration activities of other claimants.
• Blocking access to Scarborough Shoal and other features.
• Provocative actions, such as the use of water cannons against vessels.

ASEAN Instruments and Their Limits

The 2002 ASEAN–China Declaration on Conduct of Parties in the SCS and the 2017 CoC Framework were important steps toward cooperation.⁶ However, both remain non-binding and rely only on voluntary restraint. Because they lack enforcement, monitoring, and dispute‑resolution mechanisms, they have not prevented militarization or persistent tensions in the region. This shows why a binding CoC is needed — one that turns political promises into enforceable rules backed by clear procedures and accountability.

The 2016 Arbitration Award:

The 2016 SCS Arbitration ruled that many disputed features are legally “rocks” or “low‑tide elevations,” which cannot generate exclusive economic zones (EEZs). It also declared China’s “nine-dash line” claims inconsistent with UNCLOS and therefore invalid.⁷ The tribunal further found that land reclamation and construction activities caused serious environmental damage, violating obligations to protect the marine environment.⁸

These rulings are important because they remove ambiguity over maritime entitlements and highlight the risks of unilateral actions. A CoC must therefore reflect this jurisprudence, ensuring that claimant states manage disputes, navigation, and resource use in ways consistent with international law.

See also: The 2016 South China Sea Arbitral Award: Clarifying the Legal Limits of Maritime Claims.

The Need for a CoC

To promote stability and peaceful resolution of disputes in the SCS, claimant states must collaboratively develop a comprehensive and enforceable CoC. The CoC would govern the behavior of countries with territorial claims in the region — the Philippines, Vietnam, Malaysia, Brunei, Taiwan, and China, including those states that have an interest in this maritime area.

Such an agreement is a means to prevent and manage potential conflicts in disputed waters. It ensures peace, stability, and security, while promoting the resolution of disputes in line with UNCLOS, which encourages parties to settle disagreements by peaceful means of their own choice.⁹

Key aspects of the Coc should include:

1. Respect for International Law – Commitment to uphold international law, especially UNCLOS, is crucial for all parties in the SCS. UNCLOS governs maritime rights, boundaries, and responsibilities of coastal states and vessels. This framework enables sustainable use and shared benefits for all.
2. Reaffirmation of the Freedom of Navigation and Overflight – Assuring the unrestricted movement of ships and aircraft consistent with UNCLOS promotes economic growth, peaceful coexistence, scientific progress, and global security in the SCS.
3. Non-militarization and Confidence-Building Measures (CBMs) – Demilitarization and CBMs can prevent escalation of military buildup and ease tensions in the SCS. By limiting military presence and fostering communication channels, accidental conflict and mistrust are reduced. This creates a more stable environment, allowing for peaceful resolution of claims and fostering regional cooperation on shared challenges.
4. Environmental Protection – The ecosystem of the SCS faces peril from overfishing, pollution, and climate change. Collective action from all state claimants is vital for sustainable fishing and conservation. With this, protecting the environment can foster regional cooperation, benefitting biodiversity, economies, and trust.¹⁰
5. Prohibition of Coercive Actions – The CoC should explicitly prohibit the use of force or coercion to pursue territorial claims in the SCS. This prevents accidental clashes fueled by miscalculation and fosters trust, creating an environment conducive to the peaceful resolution of disputes.
6. Right to Fish in Traditional Fishing Grounds – The CoC should ensure access for fishers to traditional grounds and discourage disruptive actions. It could also establish frameworks for joint management of disputed fisheries and mechanisms to resolve fishing rights disputes.
7. Dispute Resolution Mechanisms – Finally, a comprehensive dispute settlement mechanism, with binding outcomes respected by all parties, is the cornerstone of an effective CoC. This will provide a peaceful path to resolving maritime claims in the SCS.¹¹

The Importance of a CoC

The CoC is vital for peace, stability, and preventing dominance by any one country. In a region where navies, coast guards, and civilian fleets operate in close proximity, clear rules reduce the risks of accidental incidents or confrontations. A binding CoC provides operational guidelines, ensuring encounters are managed with restraint and predictability.

Beyond security, the CoC fosters functional cooperation in environmental protection, search and rescue, disaster response, and marine scientific research. These activities build trust and demonstrate that the SCS can be a shared space for collective progress.

Most importantly, the CoC anchors peace by embedding five critical dimensions:

• Alignment with UNCLOS and the 2016 Arbitration Award. Grounds maritime claims in established international law and jurisprudence, removing ambiguity and reinforcing lawful entitlements.¹²
• Environmental Stewardship. Safeguards biodiversity and coastal livelihoods through joint monitoring and sustainable resource practices.¹³
• Compliance Credibility. Ensures commitments are enforceable by embedding verification, regular review, and binding dispute resolution.¹⁴
• ASEAN Evolution. Turns ASEAN’s declaratory diplomacy into enforceable rules that make cooperation genuine, not symbolic. ¹⁵
• Quantified Trade Stakes. Recognizes the SCS as a vital global trade artery, making stability a worldwide imperative.¹⁶

Together, these dimensions elevate the CoC from aspiration to operational instrument, reducing miscalculation, fostering cooperation, and safeguarding regional and global interests.

Conclusion

A substantive, effective, and legally binding CoC is essential for peace and stability in the SCS. It must uphold UNCLOS, integrate arbitral jurisprudence, protect the environment, and embed credible compliance mechanisms. Claimant nations must collaborate closely to transform the SCS into a beacon of stability and cooperation.

Shaped by a robust CoC, the SCS can evolve from a zone of contention into a region of trust, shared resources, and collective progress.

Footnotes

1. See generally U.N. Conference on Trade and Development, Review of Maritime Transport (2024) [Hereinafter UN Conference on Trade and Development]; ASEAN–China Declaration on the Conduct of Parties in the South China Sea, Nov. 4, 2002, [hereinafter ASEAN Declaration of Conduct]; and Chairman’s Statement of the 20th ASEAN–China Summit, Nov. 13, 2017 (Manila) [hereinafter 20th ASEAN-China Chairman Statement]. ↩︎
2. United Nations Convention on the Law of the Sea arts. 192–194, Dec. 10, 1982, 1833 U.N.T.S. 3 [hereinafter UNCLOS]. ↩︎
3. UN Conference on Trade and Development. ↩︎
4. Republic Act No. 12064, Philippine Maritime Zones Act, sec. 2(b) (Phil.). ↩︎
5. UNCLOS arts. 56, 57, 73, 76; Bill Hayton, The South China Sea: The Struggle for Power in Asia 3–7 (Yale Univ. Press 2014). ↩︎
6. ASEAN Declaration of Conduct; 20th ASEAN-China Chairman Statement. ↩︎
7. South China Sea Arbitration (Philippines v. China), Permanent Court of Arbitration, Case No. 2013‑19, Award, ¶¶ 278, 280 (July 12, 2016) [hereinafter South China Sea Arbitral Award]. ↩︎
8. Id. ¶¶ 1203(B)(13). ↩︎
9. UNCLOS art. 279. ↩︎
10. UNCLOS arts. 192–194. ↩︎
11. UNCLOS arts. 279–280. ↩︎
12. UNCLOS; South China Sea Arbitral Award. ↩︎
13. UNCLOS arts. 192–194. ↩︎
14. UNCLOS arts. 279–280. ↩︎
15. ASEAN Declaration on the Conduct. ↩︎
16. UN Conference on Trade and Development. ↩︎