Philippines Reasserts Sabah Claim in UN Submission Amid Continental Shelf Dispute

The Philippines has reignited a long-standing territorial dispute with Malaysia by reasserting its claim to North Borneo, also known as Sabah, in a formal communication to the United Nations. This move, detailed in a note verbale dated 19 March to the UN Secretary General, coincides with Manila’s bid to extend its continental shelf in the West Palawan region under the United Nations Convention on the Law of the Sea (UNCLOS). The diplomatic escalation has drawn a sharp rebuke from Kuala Lumpur, underscoring tensions over sovereignty and maritime boundaries in the South China Sea region.

The Philippine Permanent Mission to the UN stated that Manila “has never relinquished its sovereignty over North Borneo” and referenced the 1963 Manila Accord, a historic agreement between the Philippines, Malaysia, and Indonesia. The accord, signed on 31 July 1963, stipulated that the inclusion of Sabah in the Federation of Malaysia would not prejudice Manila’s claim. The Philippines reiterated its commitment to pursuing the issue through international law and peaceful dispute resolution.

This latest assertion comes as part of Manila’s broader submission to the UN Commission on the Limits of the Continental Shelf (CLCS), filed on 14 June 2024, requesting recognition of an extended continental shelf in the West Philippine Sea, particularly off western Palawan. Under UNCLOS, a continental shelf is defined as the submerged extension of a coastal state’s land territory, encompassing the seabed and subsoil up to 370 kilometres (200 nautical miles) from its coast. The Philippines argues that geomorphological evidence shows continuity between Palawan, North Borneo, and the outer edge of its continental margin, justifying an extension beyond the standard limit.

Malaysia’s Firm Rejection

Malaysia swiftly countered the Philippine position, with its Permanent Mission to the UN issuing a note verbale in 2024 opposing Manila’s continental shelf submission. Kuala Lumpur stated that it “categorically rejects” the claim, arguing that the Philippine continental margin is projected from baselines within Sabah, a state Malaysia considers indisputably part of its territory. Malaysia further urged the UN body not to examine or qualify the Philippines’ request, highlighting the deep rift between the two nations over both land and maritime claims.

The Malaysian government has long maintained that it does not recognize any Philippine claim to Sabah, a resource-rich region on the northern tip of Borneo. Sabah became part of Malaysia when the federation gained independence from the United Kingdom in 1963, though the territory’s history is mired in competing historical narratives and legal interpretations.

A History of Contention

The roots of the Sabah dispute trace back centuries, with overlapping claims involving colonial powers and local sultanates. In 1640, Spain, then the colonial ruler of the Philippines, recognized the independence of the Sultanates of Sulu and Maguindanao under a treaty. In 1704, the Sultan of Brunei reportedly ceded Sabah to the Sultan of Sulu as a reward for military assistance in quelling a revolt. By 1878, the Sultan of Sulu leased Sabah to the British North Borneo Company in exchange for annual payments, a transaction that later became a point of contention.

Disputes intensified after the death of Sultan Jamalul Kiram II in 1936, when payments ceased. The Philippines formally staked its claim to Sabah in 1962, after the sultan’s heirs authorized the government to negotiate on their behalf. Then-President Diosdado Macapagal pursued the claim with the UK, asserting Philippine sovereignty over the territory. Despite the formation of Malaysia in 1963, which saw Sabah integrated into the federation, the Manila Accord ensured that the Philippine claim remained unresolved, setting the stage for decades of diplomatic friction.

Tensions have occasionally flared into violence. In February 2013, over 200 followers of the late self-proclaimed Sultan of Sulu, Jamalul Kiram III, attempted to reclaim Sabah by occupying a coastal village in Lahad Datu, Sabah. The standoff with Malaysian security forces turned deadly on 1 March, with a shootout leaving two Malaysian police officers and 12 Filipino rebels dead. A full-scale military operation followed on 5 March, further straining bilateral ties.

Legal and Geopolitical Implications

The current dispute over the continental shelf adds a new dimension to the Sabah saga, intertwining territorial claims with maritime rights under international law. The Philippines’ submission to the CLCS is grounded in scientific data suggesting a geological connection between Palawan, Sabah, and the outer continental margin. If recognized by the UN body, this could grant Manila rights to explore and exploit resources on the extended seabed, potentially overlapping with areas Malaysia considers part of its exclusive economic zone.

However, the CLCS does not adjudicate territorial disputes, meaning any decision on the continental shelf would not directly address the sovereignty of Sabah. Legal experts suggest that a ruling in favour of the Philippines could still bolster Manila’s broader narrative of historical and legal entitlement to the region, even if it does not shift borders. Conversely, Malaysia’s opposition reflects its determination to safeguard both its territorial integrity and maritime interests, particularly in a region critical for fisheries, shipping lanes, and potential hydrocarbon reserves.

Beyond the bilateral standoff, the dispute carries implications for the wider South China Sea, where overlapping claims among multiple nations—including China, Vietnam, and Brunei—have long fuelled geopolitical tensions. The Philippines’ invocation of UNCLOS echoes its 2016 arbitral victory against China, which affirmed Manila’s maritime entitlements in the West Philippine Sea. Yet, with Malaysia rejecting the continental shelf claim outright, the prospect of a negotiated resolution appears distant.

Domestic and Regional Reactions

In the Philippines, the government’s renewed push on Sabah has drawn mixed responses. Some nationalist voices view it as a necessary assertion of sovereignty, particularly in light of Malaysia’s firm stance. Others caution against escalating tensions with a key ASEAN neighbour, emphasizing the need for dialogue over confrontation. Public sentiment, often shaped by historical grievances tied to the Sulu Sultanate, remains a potent undercurrent in Philippine politics, occasionally influencing foreign policy decisions.

In Malaysia, the government’s rejection of the claim has been broadly supported domestically, with Sabah’s integration into the federation seen as non-negotiable. Political leaders in Kuala Lumpur have framed the Philippine submission as an affront to national sovereignty, while local communities in Sabah express concern over the potential for renewed unrest, recalling the 2013 Lahad Datu incident.

Regionally, the dispute risks complicating ASEAN’s efforts to maintain unity and stability. Both nations are members of the Southeast Asian bloc, which prioritizes consensus and non-interference in internal affairs. While ASEAN has historically avoided direct involvement in bilateral disputes, the overlap of territorial and maritime claims in the South China Sea could draw wider attention, particularly if other member states perceive a threat to regional cooperation.

Looking Ahead: Pathways to Resolution?

As the UN Commission on the Limits of the Continental Shelf reviews the Philippine submission, the Sabah dispute is unlikely to see a swift resolution. Historical claims, legal complexities, and national pride on both sides present formidable barriers to compromise. Analysts suggest that confidence-building measures—such as joint resource exploration or bilateral talks on maritime boundaries—could offer a pragmatic way forward, even if the core territorial issue remains unresolved.

Yet, with both Manila and Kuala Lumpur standing firm, the potential for missteps looms large. If unaddressed, simmering tensions could spill over into diplomatic or even security challenges, particularly in a region already fraught with competing interests. For now, the eyes of Southeast Asia remain on the UN process, as well as on how both governments navigate this latest chapter in a centuries-old saga. The question lingers: can a balance be struck between historical claims and modern geopolitical realities, or will the Sabah dispute remain a perennial fault line in the region’s landscape?