The South China Sea conflict had been a battle of maps long before China deployed its warships and the Philippines engaged in multination military drills as a countermeasure in the international waterway.  

China officially claimed the Spratly Islands in 1947 with a nine-dash-line map. But Spain marked the islands as part of Philippine territory two centuries earlier—in 1734, to be exact—and had a map to show for it. 

The 1734 Murillo Velarde map depicts the Spratlys as well as Scarborough (Panatag) Shoal as part of Philippine territory, according to retired Supreme Court senior associate justice Antonio Carpio.   

The Spratlys are a large group of reefs, shoals, atolls and small islets spread out over 409,000 square kilometers in the South China Sea.

On its western section lies the Kalayaan Island Group, which includes Pag-asa, off the province of Palawan. Pag-asa is the only Philippine-inhabited island in the Spratlys that functions as a barangay of the municipality of Kalayaan in Palawan. 

Farther up north is Scarborough Shoal off the province of Zambales, coveted for its abundant fish stock and a lagoon that provides refuge for fishermen during storms. It lies within the Philippines’ 200-nautical-mile exclusive economic zone.

When Spain ceded the Philippines to the United States under the 1898 Treaty of Paris, the Spratlys and Scarborough Shoal were depicted as lying outside “treaty lines,’’ and hence excluded from Philippine territory, according to Carpio.

And there’s the rub. 

While the error was rectified in the 1900 Treaty of Washington, the misconception that the Spratlys and Scarborough are not part of Philippine territory has stuck to this day, and is even repeated by some Filipino intellectuals, Carpio said. 

Worse, he added, the misconception is gaining traction on social media.

Hence, there is the need for the government, Filipinos and institutions to craft and rally behind a “unified legal and historical narrative” on the Philippine stand amid disinformation by China and its Filipino propagandists, Carpio said. 

“We are asking our military people, Navy, Air Force, to die to defend these islands,” the retired justice said. “Why do we ask our people to risk their lives if those are not ours? It is incumbent upon our government to now finally decide what is really our historical and legal narrative.”

Carpio spoke at a workshop on West Philippine Sea reporting, which was organized by the Philippine Center for Investigative Journalism in January. 

To correct the misconception engendered by the Treaty of Paris, the Philippines must go back to the 1734 map made by the Jesuit priest, Fr. Pedro Murillo Velarde, on the Spanish King Philip’s order to Philippine Governor General Fernando Tamon.  

“Why this map?” Carpio said. “Because this is the first official map of Philippine territory ever. And it shows Panacot—that’s Scarborough Shoal. That’s the first official name of Scarborough Shoal—Panacot.” 

He added: “And we have Los Bajos de Paragua. Paragua is the old Spanish name for Palawan. Los Bajos means the Shoals of Palawan. What are the Shoals of Palawan? Those are the Spratlys.”  

Carpio said this was reiterated by the 1808 and 1875 maps—proof that only Spain claimed the Spratlys and Scarborough Shoal from 1734 to 1875. He called the Carta General of 1875 the “holy grail map” because it’s the most detailed and most complete map of Philippine territory.

(A 1657 map of the Philippines made by Nicolas Sanson, the royal cartographer of King Louis XIII of France, shows the Spratlys as part of its territory, according to the Institute for Maritime and Ocean Affairs.) 

Everything changed when the United States and Spain concluded their war with the Treaty of Paris in 1898, which showed the Spratlys and Scarborough Shoal as “lying outside the treaty lines” based on an erroneous American map.   

“So [the Americans] went back to the Spaniards: ‘Hey, there are so many islands lying outside the lines. Our agreement was we should cede to the US all the islands of the Philippine archipelago,’” Carpio said.

To correct this, he said, they cobbled the Treaty of Washington in 1900, which states that Philippine territory “includes all islands of the Philippine archipelago lying outside the lines of the Treaty of Paris.”

Much has happened since then.

France annexed the Spratlys between 1933 and 1939. Japan occupied and developed the Spratlys into a submarine base during World War II, but renounced all its claims in 1951 after losing the war. 

In 1947, China claimed the Spratlys with its nine-dash-line map that encompassed 90% of the South China Sea, and so did the Philippines, according to Carpio.

In July 2016, an arbitral tribunal invalidated China’s sweeping claim and ruled in favor of the Philippines. The case filed by the Philippines at the court was triggered by China’s occupation of Scarborough Shoal in 2012.

According to Britannica, the Philippines laid claim to the Spratlys’ Kalayaan Island Group in 1955 before occupying Pag-asa in the 1970s. Filipino civilians and soldiers and their families have since settled there; they now number 400.

Over the last decade, China has occupied islands and reefs in the Spratlys, fortifying these with military infrastructure, including radar and communications arrays, airstrips and hangars, and surface-to-air and anti-ship cruise missile systems.

China’s drawing of baselines in Scarborough Shoal in a November 2024 note verbale to the United Nations presents yet another chance for the Philippines to argue its case that it has sole sovereignty over the shoal under the Treaty of Washington.

“We cannot beat China if we don’t have a unified coherent argument that is consistent with history, the facts, and the law,” Carpio said. 

This report was produced following a three-day workshop, “Uncovering the Depths: A Training on West Philippine Sea Reporting.” The workshop organized by the Philippine Center for Investigative Reporting was held last January in Quezon City.