Navigating the South China Sea: Directions under the Philippine-Led ASEAN
- Naylah Matondang & Hang (Luna) Nguyen
- 11 hours ago
- 8 min read
Introduction
On January 1st, the Philippines officially assumed the chairship of the Association of Southeast Asian Nations (ASEAN) for 2026. Some anticipate the Philippines will make bold decisions, especially in maritime security, guided by its own national interests (Chakravati, 2026). The Philippines’ chairship in 2026 served as a testament to the unity and solidity of ASEAN’s regionalism, especially to the regional order characterised by interstate complexities and external stakeholder interest, particularly with respect to the South China Sea disputes. This article aims to elaborate on the domestic circumstances and great-power influences of the Philippines’ chairmanship, particularly in navigating the prolonged regional disputes.
Originating in the mid-20th century, the South China Sea is one of the most volatile geopolitical theatres of confrontation in Southeast Asia, characterised by asymmetrical power relations with China—a neighbouring and highly assertive contender, distinctive levels of strategic prioritisation from ASEAN Member States (AMS), and the strategic rivalry between the US and China. (Lavengood, 2023).
Over the decades, there was a growing interest in military cooperation, particularly in the maritime domain. Examples include the Major Defence Cooperation Partnership (MDCP) between the US and Indonesia, the Australia-Indonesia Treaty on Common Security, and the Vietnam-China Search and Rescue Guidelines. Simultaneously, however, pushbacks against partnerships have also surged, as the Philippines’ defence alliance with the United States (US) has instigated Beijing’s deliberate aggression through “grey zone” tactics (Puzon, 2023).
As the international landscape intensifies, owing to the unpredictable directives of US President Donald Trump, regional states are already facing China’s aggressive push to consolidate security and military cooperation (Early, 2025). It becomes imperative to secure strategic cooperation that binds the AMS’ interests. Given Southeast Asia’s unique dynamics and the Philippines’ political state, ASEAN needs to determine a strategic position to shape the current surge of political interest in the region.
Philippines Maritime Security Ambitions
The Philippines’ maritime security agenda has been shaped by decades of territorial disputes and a growing sense of urgency to protect its sovereign rights in the West Philippine Sea, notably the Philippine designation for its exclusive economic zone (EEZ) in the South China Sea. Following the landmark 2016 arbitral tribunal ruling under the United Nations Convention on the Law of the Sea (UNCLOS), which invalidated China’s 10-dash line claims and affirmed the Philippines’ rights to areas including Scarborough Shoal and the Spratly Islands, Manila has sought to assert its legal victory through both diplomatic and operational means (International Crisis Group, 2024).
Under President Marcos Jr., the Philippines has adopted a more assertive posture, increasing maritime patrols, resupply missions to Philippine-occupied features such as Second Thomas Shoal, and vocal protests against Chinese incursions (Bautista & Candelaria, 2025). The president has mentioned the ambition to reestablish the 1990s negotiations on the Code of Conduct (CoC) for the South China Sea, stating “Manila will push for a finalised and binding CoC in the South China Sea between ASEAN and China” (Chakravati, 2026).
Beyond territorial defence, the Philippines recognises the economic dimensions of maritime security: protecting Filipinos' fishing rights, ensuring freedom of navigation for commercial shipping, and exploring potential energy resources within its EEZ (Lau, 2026). As ASEAN Chair, the Philippines faces the challenge of advancing these national maritime interests while maintaining the credibility and neutrality expected of regional leadership.
The United States and China: For and Against
The Philippines’ position as ASEAN chair in 2026 is fundamentally shaped by its competing relationships with the US and China, relationships that have become increasingly polarised in recent years. The presence of the former in the Philippines’ foreign policy regarding the South China Sea has been visible for decades.
Of all Southeast Asian states, the Philippines has been closest to the US under Marcos Jr., both in defence, strategic areas of concern, and economic cooperation. This alignment has manifested in concrete policy decisions: in 2023, the Philippines granted the long-time ally access to four additional military bases under EDCA, bringing the total to nine strategic locations across the archipelago (Chang, 2023). These bases provide the US military with critical positioning in the Indo-Pacific region. The deepening security ties risk transforming the Philippines’ ASEAN chairmanship into a proxy platform for US strategic interests, potentially compromising the principles of ASEAN neutrality and centrality (Office of Assistant to Deputy Cabinet Secretary for State Documents & Translation, 2023).
Evidently, China is the least enthusiastic about this partnership. Relations between Manila and Beijing have further deteriorated as China’s assertiveness has been carried out through a ramped-up “grey zone” tactic throughout the past year. These tactics have taken increasingly aggressive forms. During 2022-2023, the South China Sea Strategic Situation Probing Initiative (SCSPI) reported approximately 21 disputes with fishermen in the area (Runxi & Tenfei, 2023).
In 2024-2025, multiple instances of water-cannon harassment of Filipino vessels have led to civilian injuries, including the widely reported incident at Second Thomas Shoal in March 2024, where a Filipino sailor lost his thumb (Mendoza, 2024). Chinese Coast Guard patrols have increased near disputed maritime features such as Scarborough Shoal, Sabina Shoal, and within the Philippines’ EEZ, with Beijing deploying its maritime militia to assert its presence and deter Filipino operations (Indo Pacific Defense Forum, 2026).
With such complicated relations with both superpowers, the Philippines’ chairmanship of ASEAN invites a more prominent US-China dynamic into ASEAN and regional institutions, possibly at the expense of and against the will of the remaining Southeast Asian nations. The central question remains whether the Philippines chooses to pursue its national security interests unilaterally or lead in accordance with regional unity, both in consideration of the institutional capacity of ASEAN.
ASEAN as Southeast Asia’s Regional Pillar
As a regional pillar, ASEAN is a mandated multilateral body with the purpose of maintaining the regional strategic interest. What’s apparent in the regional maritime security dynamics proves otherwise. ASEAN’s wave of great-power political interest positioned the region in a way that tested its neutrality. The most striking example occurred in 2012 during Cambodia’s ASEAN chairmanship, when disagreement over the inclusion of the Scarborough Shoal confrontation led to the unprecedented failure to issue a Joint Communiqué following the 45th ASEAN Ministerial Meeting (Thayer, 2012).
Similar challenges emerged during Laos’ 2016 chairmanship, when ASEAN's communiqué made no direct reference to the Philippines’ landmark UNCLOS arbitral tribunal victory against China (Putra, B., 2026). Indonesia’s Foreign Minister Marty Natalegawa subsequently conducted shuttle diplomacy to issue ASEAN’s Six-Point Principles on the South China Sea, partially salvaging ASEAN’s credibility but unable to produce a unified position on the incident itself (Azis, 2019).
China’s centrality to the regional economy creates an asymmetrical dependency that complicates ASEAN's ability to maintain its principles, thus causing isolated diplomatic failures. ASEAN-China trade in goods more than doubled over the past decade, reaching US$722 billion in 2024 and accounting for nearly one-fifth of ASEAN’s global trade, with China becoming each Southeast Asian state’s largest trading partner in goods since 2020 (ASEAN Secretariat, 2025).
This structural dependency translates into political leverage, as Beijing has a documented history of getting specific ASEAN members to withhold consensus and block ASEAN statements on South China Sea issues that conflict with its interests. The intensification of US-China strategic rivalry also introduces an external dimension that narrows ASEAN’s diplomatic space, as tensions between the two great powers are making it harder for ASEAN nations to maintain neutrality or strategic autonomy (Darmawan, 2025).
The ambition for non-linearity in certain great political powers is reflected in the 48th ASEAN Summit, where ASEAN leaders reiterated established principles regarding the South China Sea. This includes exercising self-restraint, avoiding actions that could escalate tensions, and pursuing dispute resolution in accordance with international law and UNCLOS 1982, while welcoming continued progress in Code of Conduct (CoC) negotiations guided by the 2023 ASEAN-China Guidelines (ASEAN Philippines, 2026). Thus, fulfilling the ambition requires applying a cooperative problem-solving negotiation approach to allow all parties to reach a satisfactory mediated resolution without polarising two opposing national agendas, thereby preserving ASEAN’s relevance as a regional security architecture.
Looking Ahead
The trajectory of the Philippines’ ASEAN chairmanship will ultimately be measured by its ability to uphold regional principles under conditions that discourage neutrality. The 48th ASEAN Summit’s reaffirmation of self-restraint, UNCLOS-based dispute resolution, and continued COC negotiations reflects an institutional commitment to maintaining, instead of resolving, the South China Sea dispute through collective diplomatic frameworks.
Sustaining this momentum requires the Philippines to exercise principled leadership that subordinates its bilateral grievances with other great powers in the region to the broader imperative of ASEAN cohesion. This is made possible by the Philippines' unique dual position as both a frontline claimant state and a regional convenor, uniquely placed to convert national exposure into collective ASEAN resolve.
Rather than being a source of tension, this duality may be an asset. Manila has an internal understanding of the South China Sea dispute from its legal victories, its lived experience of grey-zone aggression, and its long navigation of great-power pressures. By channelling these experiences into strengthening ASEAN’s collective maritime governance frameworks rather than advancing its bilateral agenda, the 2026 chairmanship holds genuine promise as a turning point to grow the institutional voice on the South China Sea.
This article represents the views of contributors to STEAR's online digital publication, and not those of STEAR, which takes no institutional positions.
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