Opinion | China draws red line at Scarborough Shoal after Manila’s new maritime laws

On November 10, China declared territorial sea baselines around the Scarborough Shoal, a contested area in the South China Sea. This move is part of Beijing’s broader strategy to assert territorial claims through legal and operational measures, particularly in response to recent Philippine maritime policy.

Earlier this month, Philippine President Ferdinand Marcos Jnr signed the Maritime Zones Act and the Archipelagic Sea Lanes Act into law. These laws formalise Manila’s jurisdiction over disputed waters and designate strategic maritime corridors for navigation. Drawing on an international arbitration court’s 2016 ruling, which attempted to invalidate China’s sovereignty and jurisdiction claims, the Philippines has sought to strengthen its position amid escalating tensions with China.

China responded swiftly by defining territorial sea baselines, publishing updated maps, assigning administrative codes to disputed areas and naming islands and reefs under its jurisdiction with Chinese characters. These actions underscore Beijing’s determination to cement its claims through legal channels while continuing to reject the 2016 arbitral ruling.

Critics argue that China’s selective invocation of international law under the United Nations Convention on the Law of the Sea (Unclos) undermines its legitimacy. However, Beijing’s move can be considered a calculated effort to legitimise future enforcement measures while avoiding overt military escalation, a hallmark of Beijing’s broader strategy in contested maritime areas.

In tandem with these legal measures, China has increased its physical presence around the Scarborough Shoal. The Chinese navy and coastguard have conducted intensified patrols and monitored foreign vessels.