Chinese media have just announced the invasion of Sandy Cay, or Pulo ng Bailan. This disputed feature is part of the Spratlys, or Pag-asa Islands, that the Philippines, among other countries, has a claim on. Therefore, it is imperative for the government to take decisive actions to challenge another instance of foreign occupation.

Chinese state broadcaster CCTV first reported the armed landing on Sandy Cay Reef in the West Philippine Sea, which was later picked up by Western media. CCTV then showed supposed China Coast Guard (CCG) officers unfurling the Chinese flag, signifying their claim of control.

The intrusion had long been anticipated, as Chinese coast guard and navy ships were seen close to the sandbar neighboring Philippine-occupied Thitu (Pag-asa) Island.

Geopolitical experts had warned that China was attempting to seize Sandy Cay even during the administration of President Rodrigo Duterte. But the then-Secretary of Foreign Affairs, Alan Peter Cayetano, denied the allegation.

The “takeover” of the island happened while Philippine and United States forces were conducting the annual Balikatan exercises. CCTV announced that the CCG “implemented maritime control and exercised sovereign jurisdiction” over Sandy Cay Reef.

Sandy Cay is an uninhabited sandbar in the Spratly Islands, which is a contested region claimed in part or whole by China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan.

China’s “nine-dash line,” updated to a “10-dash line” in 2023, asserts sovereignty over nearly the entire South China Sea, a claim that overlaps with the exclusive economic zones (EEZs) of several Southeast Asian nations, including the Philippines.

The CCG’s action on Sandy Cay, timed as a deliberate signal from Beijing, seeks to test the resolve of the Philippines and its allies, particularly the United States, under President Donald Trump’s new administration, which took office in January 2025.

Planting its flag on Sandy Cay, a geopolitical expert said, means China established a “fact on the ground,” a tactic it has used in other disputed features in the South China Sea, such as at Mischief Reef, where it built a major military outpost after seizing low-tide rocks in 1995.

The aggressive move signals that the Chinese government is willing to assert claims physically, despite the US-Philippine Mutual Defense Treaty, which obligates the US to defend Philippine forces in the event of an armed attack in the Pacific, including the South China Sea, such as the one that just transpired at Sandy Cay.

According to a Financial Times report, this is the first time in years that Beijing, which claims nearly the entire South China Sea, has officially raised its flag on previously unoccupied territory.

The invasion violated the 2016 Permanent Court of Arbitration (PCA) ruling, which stated that China’s “nine-dash line” and its historical claims to the South China Sea have no legal basis under the United Nations Convention on the Law of the Sea (UNCLOS).

The tribunal found that China’s actions, including land reclamation and interference with Philippine fishing and resupply missions, violated the Philippines’ sovereign rights within its 200-nautical-mile exclusive economic zone.

A significant portion of the arbitral ruling provided that no feature in the Spratlys, including Sandy Cay, qualifies as an “island” capable of sustaining human habitation or economic life, thus limiting them to “rocks” that generate only a 12-nautical-mile territorial sea, not a 200-nautical-mile EEZ.

China, however, reclaims features in the disputed region to justify its expanded territory using the UNCLOS definition.

Beijing had rejected the arbitral ruling, calling it “illegal, null, and void.” Its actions on Sandy Cay, including the flag-raising and assertion of “sovereign jurisdiction,” thus continue its strategy of dismissing international law in favor of unilateral actions.

The government has considered a second arbitration case against China, and it’s about time to make it happen.