By Remy Majangkim, Historian and Regional Activist
KOTA KINABALU: History along the maritime borderlands of the Sulu Sea is rarely written in a vacuum; it is forged by the shifting calculations of external powers.
For those observing the coastline of northern Borneo, where the physical distance between Palawan’s Balabac Island and Sabah’s Banggi Island measures a mere 50 kilometres, the rapid buildup of military infrastructure in our backyard is not an isolated event.
It is the latest chapter in a long historical chain where promises were made, broken, and rewritten to suit great-power interests.
To understand why the construction of a 3-kilometer dual-use runway on Balabac raises serious strategic questions in Kota Kinabalu and Kuala Lumpur, one must look past the polished rhetoric of diplomatic communiqués.
We must examine the concrete realities on the ground: physical force postures, unextinguished historical claims, and multi-trillion-cubic-foot gas reserves waiting beneath the Sulu Basin.
The Pattern of Discarded Pledges
The historical record in this corridor bears a consistent signature. In 1899, facing an active campaign in Luzon during the Philippine–American War, the United States negotiated the Kiram–Bates Treaty with the Sultanate of Sulu.
The agreement secured immediate non-aggression in the south under the guise of “protection.” Yet by 1904, once northern resistance was quelled, Washington unilaterally abrogated the treaty. Eleven years later, the 1915 Carpenter Agreement formally stripped the Sultanate of its temporal sovereignty, absorbing its domain into the Manila-administered colonial apparatus.
The pattern repeated itself post-World War II. Over 200,000 Filipino soldiers were conscripted into the United States Armed Forces in the Far East (USAFFE), fighting under the American flag and enduring events like the Fall of Bataan and the Death March.
They were explicitly promised full veterans’ benefits, healthcare, and equal recognition under the G.I. Bill.
Yet, in 1946, facing massive national debt and utilizing the impending independence of the Philippines as a convenient legal exit, the U.S. Congress passed the Rescission Act.
With a single line of legislation, it declared that military service by Commonwealth forces “shall not be deemed to have been active service.” Filipino soldiers became the only Allied group retroactively stripped of their full rights—a betrayal that took over six decades of agonizing legal litigation to partially acknowledge.
When history demonstrates that major powers treat treaties and pledges as temporary instruments of convenience, skepticism toward present-day strategic shifts becomes an imperative of self-preservation.
The Pacification of the Corridor and the Resource Catalyst
The internal dynamics of the Sulu Archipelago underwent a fundamental shift during the administration of former Philippine President Rodrigo Duterte.
Through severe law enforcement campaigns, anti-drug operations, and targeted weapons surrenders, criminal dens and insurgent strongholds like Abu Sayyaf—which had long plagued the borderlands with kidnapping-for-ransom operations—were systematically dismantled.
With the maritime corridor effectively cleared of non-state piracy, the structural motivation shifted from internal policing to international leverage.
The primary driver behind the sudden urgency to fortify Balabac Strait is not merely high-level geopolitical balance against third-party powers; it is energy. Recent seismic evaluations of the Sulu Sea Basin point to massive prospective recoverable gas reserves.
Under Service Contract 80, estimates for the Halcon exploration prospect have been revised upward to 8 trillion cubic feet (Tcf) of recoverable gas—potentially two to three times the size of the Malampaya field.
Whichever power holds physical surveillance, radar coverage, and forward military capacity over the Balabac and Sulu Straits effectively commands the gatehouse to one of Southeast Asia’s most lucrative untapped hydrocarbon corridors.
The View from the Shore: Security Without Illusions
From a Sabahan perspective, watching forward-operating naval facilities and long-range precision fires (such as HIMARS systems) take shape just 20 minutes across the water cannot be dismissed as routine regional defence.
The Philippine government has never formally extinguished its baseline claim over Sabah. When forward military staging grounds are constructed right along an unresolved boundary line, it alters the local balance of power regardless of official intentions.
Relying on empty talk shops or assuming foreign defence postures will remain static is a dangerous gamble. The lesson of the 1899 Bates Treaty, the 1915 Carpenter Agreement, and the 1946 Rescission Act is clear: paper promises dissolve when strategic interests change.
If the Sulu Sea is to avoid becoming a powder keg, regional security cannot rely on diplomatic window dressing. It demands hard-headed realism:
Clear Border Enforcement: Sabah and Putrajaya must maintain a strong, unyielding defence I got posture through the Eastern Sabah Security Command (ESSCOM), ensuring complete radar and naval coverage over our northern sea approaches.
Resource Vigilance: Any exploration within the Sulu Basin must strictly respect established maritime boundaries, ensuring that economic development is never used as a vehicle for creeping territorial encroachment.
Pragmatic Sovereignty: Regional dialogue must proceed with clear eyes. While trade and counter-piracy operations require functional coordination, our national sovereignty over Sabah’s soil and waters remains absolute and non-negotiable.
Standing on the island and looking across the strait, the broader picture becomes undeniable. History is repeating its old rhythms in the Sulu Sea. Recognizing the historical chains of event is our only guarantee against becoming casualty to them once again.
