TLDR
The US State Department has rejected China's attempts to enforce a national nature reserve at Scarborough Reef, calling the designation a pretext to deny Filipino fishermen access to traditional fishing grounds. The department said the US stands with its ally the Philippines, and Washington has called on China to honour a binding 2016 international tribunal ruling.
KEY TAKEAWAYS
Washington calls out a legal fiction
The label is "nature reserve". The practical effect, Washington says, would be to lock Filipino fishermen off waters their families have worked for generations. The United States Department of State issued a fresh statement at the weekend saying it "rejects China's ongoing attempts to enforce its destabilizing 'national nature reserve' at Scarborough Reef and deny Filipino fishermen access to their traditional fishing ground".[3] The statement called the designation one of Beijing's "dubious environmental and legal pretexts, backed by coercion", and closed by saying the US "stands with our Ally, the Philippines, in support of a free and open Indo-Pacific". It did not treat the proposal as a genuine conservation measure.
It is the second time Washington has rejected the designation. When Beijing first declared the reserve in September 2025, Secretary of State Marco Rubio was direct. "The United States stands with our Philippine ally in rejecting China's destabilizing plans to establish a 'national nature reserve' at Scarborough Reef," Rubio said then.[1] The State Department framed the designation as cover, using environmental and legal pretexts to deny Filipino fishermen access to traditional fishing grounds they have worked for centuries.
Scarborough Shoal, known in the Philippines as Bajo de Masinloc and in China as Huangyan Dao, is a small coral atoll sitting well inside the Philippines' 200-nautical-mile exclusive economic zone. China claims it anyway, under the nine-dash line principle, a sweeping assertion of historic rights that a 2016 international tribunal examined and dismissed. Dressing territorial control in conservation language does not change the geography; it changes the optics, and that appears to be the point.
Water cannon and a nine-year-old ruling
The dispute has not stayed abstract. In recent weeks Chinese vessels have used water cannon on Philippine vessels near Scarborough Shoal.[3] "The whole world saw it, and it's disturbing," Rubio said of the water-cannon use in July, on the sidelines of the ASEAN meeting in Manila.[3]
The legal backdrop is clear. In 2013, the Philippines initiated arbitration against China under the United Nations Convention on the Law of the Sea. The Permanent Court of Arbitration's July 2016 award dismissed China's nine-dash-line claims in the South China Sea; China refused to participate in the proceedings.[2] Beijing adopted a position of non-acceptance from the start and has maintained it ever since.
Washington's position is that the ruling is not optional. The State Department called on China to abide by the tribunal's unanimous decision, which found that China had unlawfully prevented Filipino fishermen from engaging in traditional fishing at Scarborough Reef, and described that ruling as final and legally binding.[1] The tribunal also found that Scarborough Shoal does not generate its own exclusive economic zone, directly undercutting any claim China might make to the surrounding waters.
What the waterway is actually worth
The strategic weight of the South China Sea is not hard to quantify. The Center for Strategic and International Studies estimates that more than $3 trillion worth of goods transit its waters each year.[4] Shipping lanes connecting East Asian manufacturing economies to markets in Europe, the Middle East and beyond run through these waters.
Scarborough Shoal sits near the northern entrance to those lanes. Its value as a fishing ground is real and immediate for the Filipino communities who depend on it. A nature reserve designation, if it holds, would hand China administrative control without a shot fired, which is why Washington is treating environmental framing as a security move.
Alliance obligations and the silence from Beijing
The US-Philippines Mutual Defence Treaty means Washington's language carries more than diplomatic weight. Rubio's use of the word "ally" was deliberate; the treaty creates obligations that would be triggered if Philippine forces or vessels come under armed attack, and the water-cannon incidents have already tested where that line sits.
At the time of publication, no response from Beijing to the State Department statement had been reported. China's standard position, that its sovereignty over Scarborough Shoal is "indisputable" and that the 2016 tribunal lacked jurisdiction, had not been updated in the wake of Rubio's statement. The nature reserve proposal itself has not been officially withdrawn.
The pattern is familiar to anyone who has watched the South China Sea closely. A new administrative or legal structure appears, other claimants object, and China does not withdraw. A nature reserve fits that template precisely: it creates a domestic legal instrument that China can enforce, with environmental protection as the said rationale and access denial as the operational effect. Washington's explicit rejection puts that strategy on the record as contested, for the second time in under a year.
SOURCES & CITATIONS
FREQUENTLY ASKED QUESTIONS
Where is Scarborough Shoal and why does it matter?
What did the 2016 arbitration ruling decide?
Is the US obliged to defend the Philippines over Scarborough Shoal?
Takeshi Mori writes about technology and start-ups. He is curious about how products get built and who they are really for, and he would rather see a thing working than hear it described.
