China's Sovereignty Claim Rests on a 1990 Letter to a HAM Radio Operator. The Philippines Says It's Fake.

China's embassy in Manila just escalated a territorial dispute by posting what it claims is a 1990 letter from a Filipino diplomat to a German HAM radio operator. The letter supposedly acknowledged that Scarborough Shoal wasn't Philippine territory.

The Philippines says the document is fake — or at least meaningless. But the fight over a 34-year-old letter reveals how modern territorial disputes are now waged through document dumps on social media.

The Letter

On March 14, China's embassy posted the alleged letter, reportedly written by Bienvenido Tan Jr., then the Philippine ambassador to Germany, to Dieter Löffler, a German HAM radio enthusiast. The letter supposedly stated that Scarborough Shoal "does not fall within the territorial sovereignty of the Philippines."

The Philippines' Department of Foreign Affairs called it "of uncertain origin and authenticity, and certainly without value."

"There is no merit in debating supposed documentary artifacts produced by third parties and presented as posts on social media, especially if these third parties have vested interests," said maritime affairs spokesman Rogelio Villanueva.

Why a HAM Radio Operator?

Scarborough Shoal is close enough to the Philippines that its signal has been used by radio hobbyists for decades. HAM radio operators care about whether features like Scarborough qualify as distinct "entities" for DXpedition credit — amateur radio expeditions that establish contact from rare locations.

The alleged 1990 letter may have been routine clarification for a HAM radio club about whether Scarborough counted as a separate entity from the Philippines for contest purposes. The distinction matters to hobbyists. China's embassy is now using it to assert territorial claims.

Competing Legal Positions

The Philippines claims sovereignty over Scarborough Shoal based on:

• The Murillo Velarde map of 1734, showing it as Philippine territory
• Centuries of administration, including use as a military target range
• Its location 120 nautical miles from Zambales province, well within the Philippines' exclusive economic zone

China cites historical claims under its nine-dash line, which the 2016 Arbitral Award invalidated. That tribunal found the Philippines' EEZ intact and ruled China's historical claims were legally baseless.

China has occupied Scarborough since a 2012 standoff. Chinese Coast Guard vessels now block Filipino fishermen from entering the shoal's lagoon, violating the tribunal's finding that it should be accessible as a common resource.

Engagement Is Not Concession

The Philippines' response is unusually sharp for a government trying to balance bilateral relations with territorial defense. Manila holds the rotating ASEAN chair this year and is pushing to finalize a Code of Conduct for the South China Sea.

"The Philippines makes one thing unequivocally clear: engagement is not concession," Villanueva said. "Our pursuit of dialogue reflects a calibrated and principled commitment to peaceful dispute settlement — it does not, in any manner, dilute or qualify the Philippines' firm, unequivocal positions in the West Philippine Sea."

He added that China's refusal to submit to international arbitration is a "tacit admission that its claims cannot withstand legal scrutiny."

Documentary Warfare

This isn't the first time disputed historical documents have been weaponized in the South China Sea. But posting them on social media as if a 1990 letter to a radio hobbyist settles international law is new.

The Philippines won't authenticate the document. China won't submit to another tribunal. So the dispute now plays out in press briefings and embassy statements — documentary warfare for an audience that will never see the original letter or know if it was ever real.

Scarborough Shoal remains blockaded. Filipino fishermen can't reach their traditional fishing grounds. And both sides are fighting over the meaning of a letter that may or may not have been written to a man interested in radio signals, not sovereignty.