China has identified the beleaguered garrison at Second Thomas Shoal as a weak link among the South China Sea features physically occupied by the Philippines and, by extension, the US-Philippines alliance.

While Manila has held its nerve against Beijing’s mounting pressure tactics and holds the moral high ground in the South China Sea, it’s not clear yet that it has a viable strategy to counter Beijing’s maritime juggernaut.

China is obviously willing to escalate. As it does, the Philippines, in trying to hang on, will probably need military support from the United States, its treaty ally. Another violent incident could invoke the US obligation to defend the Philippines against armed attack.

Since taking power in 2022, the administration of President Ferdinand Marcos Jr has got several important things right in the South China Sea.

First, Marcos has publicly laid out a clear and principled stance, founded on international law. This has helped generate sympathy and support for Manila as a plucky David standing up to Beijing’s Goliath. The turnaround in the Philippines’ international standing since the term of former president Rodrigo Duterte is remarkable.

The Marcos government has successfully revived international interest in the 2016 award of an ad hoc tribunal that ruled that China’s claims to Philippine waters were unlawful. The award had languished in abeyance under Duterte. Also in the legal realm, Manila on 15 June submitted an extended continental shelf claim to the United Nations, showing China it had not been intimidated from pursuing claims in the South China Sea. The continental shelf claim is likely to provoke protests from other Southeast Asian countries, but Manila has been quietly working at ameliorating boundary disputes with such neighbours, especially Vietnam.

Second, the Philippine Coast Guard’s campaign to bring transparency to China’s coercive actions in the maritime domain and information warfare has brought a new level of awareness to the South China Sea. China cannot credibly refute bullying allegations when the evidence is in plain view and on social media.

Third, in April, the president’s office created a National Maritime Council to coordinate South China Sea policy. This comprises the key government maritime stakeholders, including the departments of defence, foreign affairs and transportation; the latter oversees the Coast Guard. The new body, which met this week, should subsume the existing National Task Force for the West Philippine Sea.

Fourth, the Philippines is implementing archipelagic defence. In doing so, it is partially reconstituting the armed forces’ capabilities for external defence after decades of internal-security focus. The armed forces have acquired Brahmos cruise missiles from India for coastal defence and are fielding them in western Luzon—within range of Scarborough Shoal though not yet Second Thomas Shoal, which is far to the south. The Marcos administration has embraced a closer military relationship with the United States, resulting in increased exercises and expanded access for visiting US forces. Manila has also courted closer defence cooperation with Australia, Japan and others. These changes are collectively intended to counter-balance China’s maritime expansionism as broadly and deeply as possible.

Progress has been significant, but a number of policy shortcomings need to be addressed.

One is that the current approach is plainly insufficient. China has not been deterred from disrupting recent resupply missions by the Armed Forces of the Philippines to the garrison at Second Thomas Shoal. These have including a botched air drop and the latest attempt by small boats on 17 June, which was brazenly interdicted by China Coast Guard  personnel alongside the grounded Sierra Madre landing ship, the accommodation of the  Philippine garrison.

Also, different arms of the Philippines government issue multiple, overlapping statements on the South China Sea, suggesting there is a coordination problem. Moreover, a creeping emotionalism has coloured the language of some of these statements and related social media postings.

Third, the Philippines may have passed the point of diminishing returns from the Coast Guard’s name-and-shame campaign against China. Manila has probably realised all its diplomatic gains from the increased transparency and awareness about China’s misbehaviour, while it is clear that China will not be shamed into better behaviour for the sake of its reputation. Transparency, while useful, is not a stand-alone policy and needs back-up.

And the Philippines is paying a price for Marcos’s comment at the Shangri-La Dialogue that ‘if a Filipino citizen was killed by a wilful act, that is very close to what we define as an act of war’. He had earlier ruled out using fire hoses on its vessels to counter the China Coast Guard’s aggressive use of water cannons against Philippines vessels.

Such attempts to communicate Manila’s resolve and peaceful intentions to Beijing, while well intentioned, have only emboldened China to escalate at Second Thomas Shoal. Red lines and grey zones do not mix well with China, as Beijing is adept at blurring the former into irrelevance. Now, as a result of China’s escalation, the grey zone around Second Thomas Shoal has a much darker hue. We are perilously close to the brink of an incident that triggers the United States’ treaty commitment to defend the Philippines.

So, what lies ahead?

China appears intent on maintaining an escalatory path at Second Thomas Shoal because it believes Manila is likely to blink first. In May, Beijing announced new powers for its coast guard to arrest foreigners for ‘trespassing’ within China’s ambiguous ambit claim, even where these waters overlap with the exclusive economic zones and territorial seas of other countries. On the present trajectory, there is little reason to doubt that China will follow through by apprehending Filipino fishermen or military personnel participating in future resupply missions to Second Thomas Shoal.

The current predicament is not Manila’s fault. China is clearly the aggressor at Second Thomas Shoal. But the Philippines, as a US treaty ally, must consider the consequences before it escalates. If Manila aims to maintain active control over the feature, it is likely to require US military support in doing so. At this stage, nothing short of direct involvement by the United States appears likely to convince China otherwise. And given Washington’s patchy record of hanging the Philippines out to dry by failing to prevent China from taking control of Scarborough Shoal in 2012 and not backing Manila diplomatically after it won the award in 2016, US credibility as an ally is on the line at Second Thomas Shoal. A joint Philippines-US operation to resupply the Sierrra Madre would send a firm signal of deterrence and alliance cohesion to China. But this is ultimately a decision and a request for the Philippines to make.

Manila also needs to exert tighter control over its strategic communications, to prevent duplication, policy dissonance and over-personalisation. What the Philippines needs most of all at this juncture are cool heads, cold blood and a steady hand on the tiller.