China’s brazen interference in a routine resupply mission to a Philippine outpost reveals Beijing’s growing capability to act on developments that it thinks may impact its interests—expansively defined—in the contested South China Sea. On November 16, two Philippine civilian boats delivering provisions to the moored BRP Sierra Madre at Second Thomas Shoal (called Ayungin Shoal in the Philippines) were blocked and water-cannoned by three Chinese coast guard vessels. The episode stirred strong condemnations from Manila and other capitals. Despite a reputation for cozying up to China, President Rodrigo Duterte raised the matter in a virtual ASEAN-China commemorative summit on November 22.

The incident took place on the second day of the Philippines-United States Bilateral Strategic Dialogue (BSD) held in Washington, and a day after the Philippines and Vietnam announced the revival of the Joint Marine Scientific Research Expedition (JOMSRE). Beijing may be signaling that Manila should be cautious about agreeing to any action—whether with its longtime treaty ally, the United States, or neighbor and fellow claimant Vietnam—that may undermine China’s interests in the dispute. The initial iteration of JOMSRE ran from 1996 to 2007 with China eventually joining shortly before the effort was discontinued. China may not want to be left out again.

But in the context of a looming election, the Second Thomas Shoal incident only hardened Filipino domestic views toward China, especially among the security sector. It led some to question whether the use of civilian ships for resupply is still sustainable or whether better equipped government vessels—coast guard or navy—should do the task. More importantly, it galvanized the constituency in favor of keeping robust alliance ties with the United States to deter an increasingly assertive big neighbor.

China long expressed concern about potential Philippine moves to reinforce its position at Second Thomas. In the past, it offered to tow away the weathered tank landing ship, deliberately grounded in 1999 to serve as a Philippine garrison. The concern is not unfounded but is hypocritical given China’s massive and fortified artificial islands in the sea. Against Chinese wishes, Manila recently upgraded its facilities on Thitu, or Pag-asa, Island, its largest occupied feature in the coveted sea. It now boasts a new sheltered port, beach ramp, research facility, and an upgraded coast guard station. Rehabilitation work on a degraded airstrip is also underway, and there is a plan to turn the administrative center into a logistics hub to enhance turnaround time in resupplying other nearby outposts. The resolve shown by Manila despite friendly ties with China in recent years and amid fears that U.S. backing may further embolden the Philippines presents a dilemma for Beijing.

The prospect of a reinvigorated Philippines-U.S. alliance in the last months of the Duterte government carrying over to the next administration gives China reason to be wary. Washington is stepping up its South China Sea game. It endorsed a 2016 arbitration ruling that invalidated China’s egregious claims in the strategic waterway, committed to supporting Philippine military modernization, and showed eagerness to work with Manila to upgrade security ties to meet new challenges. This includes asymmetric capabilities and gray zone actions below the threshold of armed attack that may otherwise trigger alliance obligations. According to the Joint Vision for a 21st Century Partnership released after the BSD, the allies will negotiate bilateral defense guidelines to enhance the 1951 Mutual Defense Treaty. This approach draws a parallel from the tack pursued to upgrade the U.S. alliance with Japan. Manila and Washington also plan to hold a two-plus-two ministerial dialogue between their respective defense and foreign affairs secretaries and a bilateral maritime dialogue next year.

The recent visit by Secretary of State Antony Blinken to Indonesia and Malaysia, both crucial South China Sea coastal states, also underpins the U.S. recommitment to Southeast Asia, the heart of the Indo-Pacific, under the Biden administration. Participation in regional summits, high-level official visits, and eagerness to work with allies and partners in meeting the region’s needs from improved maritime capacity, sustainably-financed infrastructure, green energy and resilient supply chains will go a long way in deepening relations with this vibrant and strategic region. Such a reaffirmation of support to ASEAN centrality provides a good backdrop to bolster the Philippine-U.S. alliance.

With the full restoration of the Visiting Forces Agreement, which provides legal cover for American troops to enter the Philippines, the two sides are now ramping up the implementation of a 2014 Enhanced Defense Cooperation Agreement (EDCA). The latter provides for the prepositioning of U.S. military assets in the country. Beyond the current five agreed locations, both sides expressed openness to explore additional sites across the country. Such forward facilities will allow the United States to immediately respond to contingencies, whether in the South China Sea or the Taiwan Strait, enhancing its security posture in the region. But this development, in turn, may prompt China to secure similar basing access pacts with other regional countries like Cambodia or Myanmar, raising the stakes of geopolitical rivalry in Southeast Asia.

The joint vision document published after the BSD also spoke of “joint command and control capability for operations” and a “bilateral maritime framework” which expectedly raised eyebrows in Beijing. Information sharing will also get a big lift with the possible conclusion of a General Security of Military Information Agreement, or GSOMIA, between the Philippines and United States next year. It remains to be seen whether the United States will require certain conditions to seal the deal. Concerns have been raised about the penetration of Huawei gear in the Philippines and the entry of a third domestic telecom player, Dito, through a joint venture with China Telecom. If “secure communications” means disengaging with Chinese telecom equipment providers or putting caps on such engagement, it will be a setback for Chinese investments in the country and another blow to Beijing’s growing global big tech ambitions.

The Second Thomas Shoal incident shows how the South China Sea continues to beset Manila’s relations with Beijing and conversely raises the salience of strong alliance ties with Washington. All eyes will be on how the next Philippine government will handle the maritime spat and deal with the two competing powers.

About Lucio Blanco Pitlo III

Lucio Blanco Pitlo III is a Research Fellow at the Asia-Pacific Pathways to Progress Foundation and a member of the Board of Directors of the Philippine Association for Chinese Studies. He was a lecturer at the Chinese Studies Program of Ateneo de Manila University and the International Studies Department of De La Salle University (Manila). He obtained his Master of Laws from Peking University and is presently pursuing his MA International Affairs at American University in Washington D.C.