Upholding Maritime Law: A Unified Stand Against China’s South China Sea Coercion – Analysis

The waters of the South China Sea have become an arena of pronounced strategic contestation in 2025, exemplified by recurrent incidents such as the 5 May encounter between the Philippine Navy’s BRP Emilio Jacinto and two Chinese frigates near Scarborough Shoal.

This analysis contends that China’s aggressive actions represent a deliberate violation of international maritime law and the South China Sea Code of Conduct. These maneuvers exacerbate regional instability and require a strong collective response from ASEAN, supported by the European Union and the United States, to curb China’s rising assertiveness and uphold the rules-based order.

Incidents over the past two years highlight a significant increase in maritime coercion. An analysis by the Quincy Institute reveals that reported maritime incidents between China and the Philippines rose by forty percent from 2022 to 2024. In 2023, there were over thirty documented “unsafe encounters,” up from twenty in 2022.

In January 2025, a Philippine Coast Guard aircraft monitoring a civilian volunteer mission at Scarborough Shoal spotted nineteen Chinese vessels, including a navy ship and multiple coast guard cutters, deploying barriers and engaging in aggressive maneuvers within the Philippines’ exclusive economic zone. These patterns not only violate the United Nations Convention on the Law of the Sea, to which China is a signatory, but also directly contravene the 2002 Declaration on the Conduct of Parties in the South China Sea, which was specifically established to prevent confrontations.

China’s refusal to adhere to the spirit of the  Code of Conduct of the South China Sea undermines the framework intended to ensure fairness for all. While Myanmar and Cambodia, along with other ASEAN members, have publicly supported a binding code, Beijing has consistently postponed the formalization of enforceable, rules-based arbitration and has rejected adjudication mechanisms. In statements, the People’s Liberation Army’s Southern Theatre Command accused Philippine vessels of “attempting invasion” and claimed to have mobilized naval and air assets to “expel” them, despite the 2016 Permanent Court of Arbitration ruling that invalidated the nine-dash line claims. By disregarding legally binding awards, arbitration, and diplomatic commitments, China undermines the framework that ASEAN has established to manage disputes. This erosion of confidence in regional norms emboldens coercive tactics.

ASEAN’s response has been cautious, issuing a consensus-driven communiqué that condemns “unnecessary escalation.” However, Beijing rarely offers explicit substantive countermeasures. To address this trend, ASEAN needs to move decisively from rhetoric to practical pressure and deterrence. A credible strategy should involve establishing a shared maritime domain awareness architecture that combines satellite imagery with automatic identification systems. Additionally, ASEAN should create a joint incident-response task force tasked with investigating and reporting violations, and implement a formal mechanism to flag noncompliance with UNCLOS for collective diplomatic censure. These measures would strengthen ASEAN’s central role and increase the diplomatic and reputational costs associated with further coercion.

International support for ASEAN is crucial. The European Union, which conducts over $103 billion in annual trade through Southeast Asian sea lanes and holds significant stakes in regional energy projects, should leverage its diplomatic influence by publicly reaffirming the United Nations Convention on the Law of the Sea (UNCLOS) and the Code of Conduct framework.

Additionally, the EU should deploy civilian survey vessels and scientific missions to contested areas. Conditioning development aid and trade preferences on improvements in maritime governance would incentivize compliance and demonstrate the EU’s commitment to a rules-based order. Furthermore, the United States must continue to uphold and expand its Freedom of Navigation Operations (FONOPs) in contested waters. In the first half of 2025, U.S. naval vessels conducted six FONOPs in the South China Sea, matching the total number from the previous year. This demonstrates a strong message of deterrence to Beijing, indicating that its claims will not go unchallenged.

Moreover, the annual Balikatan exercises involve over fourteen thousand personnel from the Philippines and the United States, highlighting the benefits of intensified security cooperation. These coordinated drills encompass maritime patrols, amphibious landings, and integrated air defense sequences, enhancing the Philippines’ readiness and underscoring the interoperability of allied forces under common command structures. Inviting EU observers and like-minded partners like Japan and Australia would expand the network of deterrence and strengthen practical ties, increasing the costs of any future acts of aggression.

Critics argue that adopting rigid positions may provoke the very conflict it aims to prevent. However, history shows that unchecked aggression often encourages further escalation. The prolonged standoff at Mischief Reef during the 1990s and 2000s intensified because no credible punitive measures were implemented, leading to China’s gradual fortification and permanent occupation of the area. In contrast, a well-balanced strategy that incorporates diplomatic condemnation, targeted economic pressure, and visible military signaling can strengthen deterrence without triggering open hostilities. Strategic support, combined with patience and backed by external offers, provides the most promising path to sustainable stability and respect for international law.

In conclusion, the confrontations in the South China Sea in 2025 mark a pivotal moment for both Southeast Asia and the international community as a whole. China’s aggressive tactics, which include perilous naval maneuvers, systematic violations of UNCLOS, and repeated disregard for the Code of Conduct of the South China Sea, directly challenge the rules-based maritime order. To address this, ASEAN must shift from its consensus-driven approach to a more proactive enforcement regime. This new strategy should be supported by enhanced joint maritime awareness, established incident protocols, coordinated responses, and unified diplomatic efforts for censure.

Finally, this stance must be supported by strategic backing from the European Union, utilizing conditional economic and civilian instruments and missions, as well as by the United States through Freedom of Navigation Operations (FONOPs) and sustained, expanded joint exercises like Balikatan. Only through coordinated efforts can this approach inform the region, ensuring that the South China Sea remains a conduit for cooperation and lawful commerce, rather than a flashpoint for great power confrontation.

The opinions expressed in this article are the author’s own.

                                                         Reference

• Blanchard, Ben. “China military says it ‘drove away’ US destroyer in South China Sea.” Reuters, 10 May 2024.
• ASEAN urges early accord on South China Sea code, end Myanmar violence.” Reuters, 13 October 2024.
• Brunnstrom, David. “U.S. backs Philippine forces in South China Sea with task force.” Reuters, 21 November 2024.