A heated Senate floor debate between Rodante Marcoleta and Francis "Kiko" Pangilinan over the West Philippine Sea has exposed deep political divisions in Manila that threaten to undermine the country's sovereignty claims against China.
During Monday's session, Senator Marcoleta argued that the Philippines must "define the coordinates" of the West Philippine Sea before it can effectively defend its exclusive economic zone. "It seems someone is claiming what's ours, but we haven't yet defined what is ours," Marcoleta said, according to Senate transcripts.
Senator Pangilinan countered by emphasizing the 2016 arbitral ruling—the landmark Permanent Court of Arbitration decision that invalidated China's nine-dash line claims and affirmed Philippine sovereignty over waters within its 200-nautical-mile exclusive economic zone.
The exchange reveals more than procedural disagreement. Marcoleta's position—that the Philippines lacks clear legal definition of its maritime territory—echoes talking points Beijing has promoted to muddy the waters around the 2016 ruling. The arbitral award already defined Philippine maritime entitlements under international law; questioning whether those boundaries are sufficiently "coordinated" suggests either legal confusion or deliberate ambiguity that serves China's interests.
For observers of Philippine politics, Marcoleta's stance reflects the persistent influence of pro-China factions within Manila's political establishment, a legacy of former President Rodrigo Duterte's pivot toward Beijing. President Ferdinand Marcos Jr. has taken a harder line on the South China Sea, strengthening defense ties with Washington and Tokyo, but domestic political divisions complicate efforts to present a unified front.
Ten countries, 700 million people, one region—and in Manila, the debate over how to defend Philippine waters increasingly splits along factional lines that have little to do with maritime law and everything to do with China's ability to cultivate political support within ASEAN capitals.
The West Philippine Sea remains the most volatile flashpoint in Southeast Asia, with Chinese coast guard vessels regularly harassing Philippine fishing boats and resupply missions to Second Thomas Shoal, where Manila maintains a small military outpost aboard the grounded BRP Sierra Madre. The Marcos administration has responded by allowing international media to document confrontations, raising the political cost of Beijing's gray-zone tactics.
But without domestic consensus on defending the 2016 ruling, the Philippines risks signaling to Beijing that patience and pressure can erode Manila's resolve—exactly the outcome China seeks across contested waters from Scarborough Shoal to the Spratly Islands.
