Naval tensions in the South China Sea have once again flared, as the Philippines, Australia, and Canada staged a bold joint maritime exercise near the fiercely contested Scarborough Shoal in early September 2025. The two-day operation—culminating on September 3—marked a significant display of unity among so-called "middle powers," determined to challenge China's sweeping maritime claims and assert their own rights in the region.
The Scarborough Shoal, located just 232 kilometers west of Luzon, the Philippines’ main island, has been under Chinese control since a tense standoff in 2012. Despite an international arbitral tribunal ruling in Manila’s favor in 2016, Beijing has refused to relinquish its grip, continuing to assert near-total sovereignty over the South China Sea based on its controversial nine-dash line map. The shoal, known locally as Bajo de Masinloc, remains a flashpoint for regional tensions, drawing in not just regional claimants but also global powers concerned about freedom of navigation and the rule of law.
This latest cooperative sail, led by the Philippine Navy’s guided-missile frigate BRP Jose Rizal (FF150), was joined by the Royal Australian Navy’s HMAS Brisbane and the Royal Canadian Navy’s HMCS Ville de Québec. The coalition wasn’t just for show. Over the course of the drills, the trio of ships formed up in tight formation near Scarborough Shoal, conducting complex maneuvers designed to sharpen maritime domain awareness and coordination. One of the most daring moments saw Australian and Filipino troops transfer between ships while underway—a feat that requires precision and trust.
According to the Asia Times, the highlight of the exercise came when an Australian intelligence-gathering aircraft flew overhead, demonstrating its capability to track movements in the contested waters. Meanwhile, a disarmed submarine drone was deployed in an "exercise box" just south of the shoal, as part of a coordinated anti-submarine warfare drill aimed at detecting and localizing underwater threats. Lieutenant Junior Grade Prince Charles Bauyot, the anti-submarine warfare officer aboard the BRP Jose Rizal, explained to reporters, "The exercise was meant to detect, localize, and recognize underwater threats." He later described the Chinese presence as "interlopers," but noted that their ships—two People’s Liberation Army Navy (PLAN) vessels, a destroyer and a frigate—kept their distance, shadowing the exercise from about 20 nautical miles away. "We are monitoring them and we have challenged them multiple times," Bauyot added. "Our exercise box is within the Philippines’ exclusive economic zone, with participating ships sailing within our territorial waters."
China’s reaction was swift and pointed. The Southern Theater Command of the PLA confirmed it had conducted a "routine patrol" in the South China Sea on September 3, but accused the Philippines of "colluding with countries outside the region to stage so-called ‘joint patrols,’" according to Caliber.Az. Tian Junli, the command’s spokesperson, warned, "Any attempt to stir up trouble in the South China Sea and create tensions is doomed to fail." He insisted that PLA forces remain on high alert to defend China’s territorial sovereignty and maritime rights. The Chinese ships shadowed the drills but, according to the Associated Press, did not directly intervene.
Notably, the United States also made its presence felt, deploying a P-8A Poseidon surveillance aircraft over the region during the exercises. This move underscored the growing internationalization of the South China Sea dispute and Washington’s enduring commitment to its longtime treaty ally, Manila. As Filipino security analyst Chester Cabalza told Asia Times, "The trilateral maritime cooperative among middle powers Australia, Canada and the Philippines near the Scarborough Shoal is the boldest show of force on freedom of navigation. Even without the United States in the equation, it conveys that every nation has the right to sail in Manila’s exclusive economic zone."
The drills also featured simulated air defense exercises, with at least three fighter jets and two combat helicopters participating in coordinated defensive maneuvers against mock aerial threats. The Philippine Armed Forces (AFP) stated, "This engagement reaffirms the Armed Forces of the Philippines’ commitment to advancing defense cooperation with like-minded nations." These activities were among the final stages of Exercise Alon 2025, the largest-ever bilateral military drill between Australia and the Philippines, involving over 3,600 personnel in 15 days of live-fire and battle maneuvers.
The context for these maneuvers is fraught. In early August 2025, a high-speed collision occurred near Scarborough Shoal when a Chinese Navy ship and a China Coast Guard vessel attempted to block a Philippine Coast Guard boat. The China Coast Guard ship sustained severe bow damage and was later repaired at Hainan Island’s Yulin Naval Base, Reuters reported. This incident was followed by a U.S. Navy freedom of navigation operation within 30 nautical miles of the shoal, further signaling Washington’s resolve to challenge what it views as China’s "excessive territorial claims." The United States has repeatedly affirmed it stands ready to assist the Philippines if hostilities break out in the region, a warning Beijing is unlikely to ignore.
Despite the high-stakes backdrop, the Philippine outpost on Scarborough Shoal was successfully resupplied in early September, a logistical feat achieved amid persistent Chinese military maneuvers. The Associated Press noted that, during the late August drills, Chinese Coast Guard, Navy, and militia ships did not directly respond to the exercises, though their presence in the area remains a constant source of tension for Filipino mariners and fishermen.
For Australia and Canada, participation in these drills signals a growing willingness among middle powers to play a more assertive role in Indo-Pacific security. As Cabalza observed, "Australia carves its own unique identity in its strategic partnership with the Philippines. Canberra has redefined its role with Manila as a reliable and close partner in the Indo-Pacific region." While Australia is not expected to sign a mutual defense treaty with the Philippines akin to the 1951 Manila-Washington pact, its actions—along with those of Canada—represent a significant step in constructing customary practices and confidence-building mechanisms in the West Philippine Sea.
China, for its part, continues to frame the dispute as an issue of sovereignty and regional stability, accusing outside actors of meddling in what it sees as its backyard. The Southern Theater Command’s warnings have become a familiar refrain, but so too has the resolve of the Philippines and its partners. Manila’s willingness to defy Beijing, bolstered by support from Canberra, Ottawa, and Washington, marks a new chapter in the ongoing contest for the South China Sea.
As the dust settles from the latest round of drills, one thing is clear: the Scarborough Shoal remains a crucible for regional rivalries and a barometer for the balance of power in the Indo-Pacific. With each passing exercise, the stakes grow higher—and the world watches ever more closely.