From Manila to Beijing, the waters of the South China Sea are inexorably rippling again. While diplomacy tries to contain the tension, signals coming from both capitals show a crescendo of assertiveness and a progressive hardening of positions, with the risk of a territorial dispute becoming a new test for the regional order and the credibility of the law of the sea.

Words that weigh like warnings

Beijing called on Manila to ‘give up unrealistic illusions’, in language that, in the Chinese diplomatic lexicon, sounds more like a threat than advice. Chinese Defence Ministry spokesman Zhang Xiaogang accused the Philippines of ‘staging farces at sea’ and ‘orchestrating propaganda scenes’, referring to Manila’s recent claims of sovereignty over the Kalayaan Islands and Scarborough Shoal (Bajo de Masinloc).
The statements come in response to a statement by the Philippine Department of Defence, posted on social media, which reiterated how these territories are ‘an integral part of the Philippine archipelago’, by virtue of ‘centuries of legal history’ and ‘international treaties’ and the UN Convention on the Law of the Sea (UNCLOS), which long predate the birth of the People’s Republic of China.

The Scarborough Shoal Knot

Scarborough Shoal, known in China as Huangyan Dao, is located about 120 nautical miles off the Philippine coast, within Manila’s Exclusive Economic Zone (EEZ). It is a small triangle of reefs and coral reefs, but its strategic importance is enormous: it lies along crucial shipping routes for global trade and in waters rich in fish resources and, according to some estimates, hydrocarbons.
Control of this area allows not only for projecting military force into the heart of the South China Sea, but also for consolidating a presence in a quadrant considered vital to the region’s energy and food security. Despite the decision of the Permanent Court of Arbitration (PCA) in The Hague in 2016 – which had invalidated Chinese claims based on the so-called ‘nine-stretch line’ – Beijing continues to reinforce its position with dual-use constructions on reefs, more frequent patrols, and increasingly muscular language.

Military exercises and the clear message to Washington

In the same hours as the diplomatic tone turned sour, the Chinese Maritime Safety Administration announced new military exercises in the waters southwest of Scarborough Shoal. The manoeuvres, which lasted a few hours, took place just as the Philippines, the United States and other regional partners were concluding planned joint naval exercises.
The time coincidence is no coincidence: the signal is one of mutual deterrence. According to regional military sources, it was a direct response to the cooperation between Manila and Washington, which has intensified in recent months through the Enhanced Defense Cooperation Agreement (EDCA), with US access to additional Philippine sites. Beijing, for its part, reads this alliance as a provocation and a threat to its maritime security, calling the exercises ‘an attempt to destabilise the region’ and to ‘internationalise’ a dispute that it would like to remain bilateral.

Diplomacy under pressure

The Philippines, led by Ferdinand Marcos Jr.‘s government, which alternates between firmness and caution, seeks to avoid escalation but does not intend to back down under international law. Manila continues to invoke the principle of territorial sovereignty as defined by 20th century treaties and UNCLOS, while Beijing insists on rejecting any external arbitration.
The language used by both countries reflects this growing tension: on the one hand, China claims the ‘historic and indisputable’ right to exercise sovereignty over the disputed islands; on the other hand, the Philippines emphasises that respect for international rules and freedom of navigation (FONOPs) is essential for the stability of the entire region.

An increasingly fragile balance

Despite calls for dialogue, the reality on the ground shows a picture of progressive ‘maritalisation’ of confrontation. Warships, coastguards and maritime militias on board fishing boats now cross each other daily in those waters, in a climate of constant provocation. Beijing does not shy away from showing its strength towards the Philippine-flagged fishing boats, even by means of water cannons and interdiction manoeuvres, and the incidents of risk of collision multiply.
Numerous think tanks warn that although there are no immediate signs of an armed confrontation, the combination of incidents, rhetoric and military pressure risks turning a territorial dispute into a strategic detonator. In a global context in which the balance is being redefined between Washington, Beijing and theAssociation of Southeast Asian Nations (ASEAN) partners, even a single low-level incident can produce unintended escalation with consequences that transcend the South China Sea.