Philippines Faces Escalating Chinese Grey Zone Tactics 10 Years After 2016 Maritime Ruling

MANILA – A decade after a landmark international tribunal dismantled Beijing’s expansive maritime claims, the Philippines is facing a sophisticated escalation of “grey zone” tactics designed to render the legal victory obsolete through physical coercion and information warfare.

The 10th anniversary of the 2016 Arbitral Award has shifted from a celebration of legal sovereignty to a critical inflection point in Indo-Pacific security. The ruling, issued under the dispute-settlement mechanisms of the United Nations Convention on the Law of the Sea by a tribunal constituted at the Permanent Court of Arbitration in The Hague, invalidated China’s “nine-dash line” and affirmed the Philippines’ sovereign rights over its 200-nautical-mile exclusive economic zone (EEZ), known locally as the West Philippine Sea.

While the ruling provides the legal bedrock for Manila’s claims, the operational reality on the water has deteriorated. China has transitioned from simple presence to a strategy of illegal, coercive, aggressive, and deceptive (ICAD) activities, utilizing the China Coast Guard (CCG), the People’s Liberation Army Navy (PLAN), and a state-backed maritime militia to exert control and test the limits of international and domestic enforcement.

The Expansion of Grey Zone Tactics

Recent data suggests a strategic shift in Beijing’s approach, moving beyond remote reefs to challenge the Philippines closer to its mainland and key sea lanes. According to the 2025 Philippine Coast Guard Review, CCG intrusive patrols have tightened their radius around the island of Luzon, with one recorded patrol coming within 30 nautical miles of Pangasinan province-waters that fall squarely within the Philippine EEZ and are critical to the country’s food security and coastal economies.

This physical encroachment is paired with “lawfare”-the use of domestic legislation and regulatory instruments to justify international incursions. On 11 September 2025, China unilaterally declared a national “nature reserve” at Scarborough Shoal, an area firmly within the Philippine EEZ. By framing the seizure of a 3,524-hectare coral reef as an environmental initiative under Chinese domestic law, Beijing has created a pretext to bar Filipino fisherfolk from their traditional grounds and to enforce exclusion through its coast guard and maritime militia. Philippine officials warn that such moves, if left uncontested, risk normalizing unilateral administrative control over internationally disputed waters.

The aggression has also turned violent. On 12 December 2025, the Philippine Coast Guard reported that nearly two dozen civilian fishing boats were targeted by CCG water cannons near Sabina Shoal (Escoda Shoal), located just 75 nautical miles from Palawan and along routes used by resupply missions to Philippine outposts. This incident marked a significant escalation: the first time the CCG targeted civilian vessels with water cannons in these waters, raising fresh questions in Manila about rules of engagement, the protection of small-scale fishers, and the threshold at which treaty commitments with allies could be invoked.

Information Warfare and Diplomatic Sanctions

Beyond the maritime domain, Manila is battling a concerted campaign of “public opinion warfare” that directly intersects with governance and public communication. The Chinese Embassy in Manila has utilized social media to target high-ranking Philippine officials, aiming to discredit and demoralize the administration’s transparency initiative, under which the government releases images, video, and incident reports from the West Philippine Sea.

Key targets include Rear Admiral Jay Tarriela, the spokesperson for the West Philippine Sea, and Secretary of National Defense Gilberto Teodoro. In a move that signals an intensification of diplomatic pressure, the Chinese Foreign Ministry imposed sanctions on Teodoro, prohibiting him and his family from entering mainland China, Hong Kong, and Macau. Philippine security officials view the measure as a direct attempt to shape elite decision-making by raising the personal and financial cost of a hard line on maritime rights.

As the anniversary of the ruling approached, the Chinese Embassy launched a digital campaign to undermine the legitimacy of the 2016 decision, recirculating Beijing’s longstanding narrative that the tribunal “has no jurisdiction.” The Philippine Department of Foreign Affairs responded by reaffirming that

“the award is final and binding and has become an unassailable part of the corpus of international law, providing legal clarity regarding maritime rights and entitlements in the South China Sea.”

That statement, officials stress, is now a central plank of Philippine foreign policy, guiding how agencies coordinate positions in international fora and how they craft domestic legislation on maritime zones, fisheries management, and defense planning.

Political Volatility and the 2028 Horizon

The sustainability of Manila’s current “robust” posture depends heavily on domestic political continuity and institutional checks. President Ferdinand Marcos Jr. has repeatedly warned that the security of the West Philippine Sea requires a consistent approach across successive administrations, not just ad hoc responses to individual incidents.

However, the upcoming 2028 presidential election introduces significant geopolitical and policy risk. Vice President Sara Duterte-daughter of former President Rodrigo Duterte-currently leads preference polls despite fluctuations in her popularity. Her father’s presidency was characterized by a strategic pivot toward Beijing and a willingness to accommodate Chinese interests in exchange for economic investment, including shelving or downplaying the 2016 ruling in early years of his term.

While Sara Duterte has remained silent on recent CCG aggressions, analysts note that her potential ascension to the presidency could signal a return to the accommodationist policies of the previous administration. Such a shift would reverberate through defense procurement, the implementation of basing access agreements, and budget allocations for the Philippine Coast Guard and Navy. To counter this risk, Manila is attempting to institutionalize its security partnerships-including the Mutual Defense Treaty with the United States and burgeoning ties with Japan and Australia-so that they are embedded in law, multi-year defense plans, and bureaucratic routines that are harder to unwind by a single administration.

Strategic Frameworks for Defense

To mitigate the threat of a policy reversal in 2028, the current administration is advocating for a “whole-of-nation” approach. This strategy aims to move beyond temporary diplomatic wins toward long-term structural safeguards that bind together executive agencies, the legislature, local governments, and the security sector.

• Institutionalization: Embedding maritime security agreements into statute, executive issuances, and multilateral frameworks to prevent a single leader from unilaterally dismantling alliances or reversing standing rules of engagement in the West Philippine Sea.
• Interoperability: Increasing joint patrols, exercises, and technical integration with partner navies and coast guards to demonstrate a persistent presence and to standardize protocols for responding to grey zone incidents.
• Public Consensus: Leveraging the fact that approximately 86% of Filipinos now favor strong alliances to defend the maritime domain, according to recent national polling, thereby creating a political cost for any future leader who chooses capitulation or significantly downgrades alliance commitments.

Manila’s approach is also tied to governance reforms at sea: efforts to modernize maritime domain awareness systems, clarify agency mandates among the armed forces, coast guard, and fisheries authorities, and align domestic legislation with the 2016 ruling and the underlying arbitration proceedings. The Philippines continues to operate under the framework of UNCLOS and the tribunal’s award, while China continues to reject the tribunal’s jurisdiction and findings, setting up a long-term contest between international law and power-based enforcement in one of the world’s most strategically vital waterways.