Few issues are as loudly debated yet so poorly understood as the West Philippine Sea. We hear strong words about patriotism, sovereignty, and “historic rights,” often shouted across social media where emotion drowns out fact. Yet many of our countrymen do not realize that the Philippines stands on one of the strongest legal foundations in modern international law: the United Nations Convention on the Law of the Sea, (Unclos).
Signed by 168 countries and in force since 1994, Unclos is what keeps the oceans from returning to the age of empire. It replaced the old system of “whoever found it first” with a rules-based order that defines territorial seas, exclusive economic zones, and continental shelves by measurable geography, not by centuries-old maps. Under Unclos, every coastal state is guaranteed 200 nautical miles of economic rights from its baselines. For an archipelago like ours, that means the waters between our islands and up to the edge of that boundary belong not to old memories but to present law.
This is why the 2016 Arbitral Tribunal ruling was historic. It affirmed that China’s “nine-dash line” has no legal basis under Unclos and that the Philippines retains sovereign rights within its Exclusive Economic Zone. The tribunal also found that China violated those rights by blocking Filipino fishers and damaging the coral reefs around Bajo de Masinloc, or Scarborough Shoal. It was a global recognition that the sea cannot be claimed by nostalgia.
China has ignored the ruling, but the law remains. Its authority rests not on force but on the consensus of nations that have chosen order over ambition. Across the world, that same law has prevailed again and again over the arguments of history.
In Somalia v. Kenya (2021), the International Court of Justice rejected old colonial-era boundaries and instead drew a new maritime line based strictly on Unclos principles. In Ghana v. Côte d’Ivoire (2017), the tribunal applied the same method — equidistance and relevant circumstances — rather than relying on British charts drawn a century earlier. Even in the Mauritius v. Maldives (2023) and Nicaragua v. Colombia (2023) cases, historical maps gave way to modern law.
The same reasoning guided the South China Sea Arbitration. The tribunal made it clear that “historic rights” cannot exist where Unclos already defines the limits of maritime zones. Ancient maps may tell stories of exploration, but they no longer draw the borders of the sea.
This is why the Philippines’ legal claim is not a colonial hand-me-down. It is the product of a modern treaty that Filipinos helped shape. Senator Arturo M. Tolentino, who led the Philippine delegation to the United Nations Conference on the Law of the Sea, was among the thought leaders behind the archipelagic doctrine now written into Unclos. His 1982 work The Philippines and the Law of the Sea articulated a vision in which archipelagic nations would be treated as unified maritime states, not as scattered islands to be divided by others.
That vision now protects us. Every time we assert our rights under Unclos, we stand not on borrowed authority but on a law built with Filipino intellect and diplomacy.
So when critics call the Murillo Velarde map irrelevant or a “hoax,” they miss the larger point. The debate today is not about who first named the reefs or charted the waters; it is about who abides by the law that the world agreed upon.
The sea remembers its past, but it now flows under a higher principle — one that measures justice not by might, but by distance, geography, and consent. That is the quiet power of Unclos: it ends the rule of empires and begins the rule of law.