President Joe Biden will warn China about its increasingly aggressive activity in the South China Sea this week during summits with Japanese Prime Minister Fumio Kishida and Philippine President Ferdinand Marcos Jr.
Two senior US officials said Biden would express serious concern about the situation around the Second Thomas Shoal, a submerged reef that is one of many contested features in the Spratly Islands.
The Chinese coastguard has used water cannons to prevent the Philippines from resupplying marines stationed on the Sierra Madre, a rusting ship that Manila intentionally grounded on the reef in 1999 in an effort to reinforce its claims to the feature.
Biden will stress that the US-Philippine Mutual Defense Treaty applies to the Sierra Madre, said the officials, adding that he expressed “deep concern” when he spoke to President Xi Jinping on Monday.
“China is underestimating the potential for escalation. We’ve tried to make that clear in a series of conversations . . . that our mutual defence treaty covers Philippine sailors and ships and by extension . . . the Sierra Madre,” one official told the Financial Times.
“China needs to examine its tactics or risk some serious blowback,” they added.
The clashes between China and the Philippines are part of escalating tensions over the South China Sea. While Beijing claims the sea almost in its entirety, its assertion clashes with claims and control of parts of it by Vietnam, Malaysia, Brunei, Taiwan and Indonesia.
China says Manila is bringing construction materials to the shoal to reinforce the Sierra Madre, which is at risk of disintegrating. It also accuses Manila of reneging on a promise years ago to remove the ship — a claim the Philippines has rejected.
Admiral John Aquilino, head of the US Indo-Pacific Command, recently issued a similar warning to a delegation of retired Chinese military officers and Cui Tiankai, China’s former ambassador to the US, according to people familiar with the situation. Indopacom did not comment.
The Biden administration has also enlisted other retired US officials to deliver similar private messages to Beijing.
The officials said the US was wary of establishing a “red line” with Beijing. “If you give the Chinese a red line, they will go just short of that and do everything but,” said one official.
The second official said China may think its actions fall below the threshold of the US commitments under the mutual defence treaty.
“The reality of their rules of engagement and the way that responsibility evolves may mean that ultimately they don’t have perfect control over that fact,” the official said. “We would not want to create an artificially clean distinction when they themselves are not fully able to control their own actions.”
Bonnie Glaser, a China expert at the German Marshall Fund, said the “greatest risk of a direct US-China military confrontation today is at Second Thomas Shoal”.
“If Beijing directly attacks Philippine ships or armed forces, Washington would be compelled to respond,” she said. “A major political crisis between the US and China would ensue, and, at worst, a wider military conflict.”
Jose Manuel Romualdez, Philippine ambassador to the US, said the two allies hoped that the treaty would never have to be invoked, but warned, “we will not hesitate to do so” if warranted.
A 2016 UN arbitral tribunal ruled that Beijing’s claim to the South China Sea is in violation of the UN Convention on the Law of the Sea because it claims waters around rocks and shoals, which do not allow claiming territorial waters, and because it partly bases its assertions on historic rights.
Second Thomas Shoal lies inside the Philippines’ exclusive economic zone, waters stretching 200 nautical miles off the coast where Unclos gives states exclusive rights to economic use.
Dennis Wilder, a former top CIA China analyst, said Beijing was trying to test what the US response would be if China attempted to remove the Philippine marines from the Sierra Madre and destroy the vessel.
He said it probably wanted to build a military outpost on the reef as it has done elsewhere in the South China Sea.
“A base closer to the Philippines would both secure China’s claim in the area and provide a forward operating location for combat operations against US forces operating from Philippine territory in a Taiwan Strait conflict,” said Wilder.
Jeff Smith, an Asia expert at the Heritage Foundation, said the US should adopt a tougher stance. “The US should participate in joint resupply missions with Filipino forces and explore options to replace the deteriorating Filipino ship,” he said.
“The US cannot repeat the same mistakes it made in 2012, when China set a terrible precedent by using military coercion to seize control of Scarborough Shoal from the Philippines.”
Underscoring the rising concern about the Second Thomas Shoal, the US, Japan, Philippines and Australia announced that they would hold their first-ever joint military exercises in the Philippines’ exclusive economic zone.
In a joint statement, the defence ministers from the four countries made clear they supported the result of a 2016 arbitration case at The Hague which rejected Chinese claims of historic rights to most of the South China Sea within a demarcation called the “nine-dash line”.
The Chinese embassy in Washington said Xi stressed in his call with Biden that Beijing had sovereignty over the Spratlys, including Second Thomas Shoal. It said the “root cause” of the dispute was that Manila had “repeatedly gone back on its words and tried to build permanent outposts on the uninhabited reef”.
“The US is not a party to the South China Sea issue, yet it keeps meddling in the issue, sowing discord concerning maritime issues between China and the Philippines and falsely accusing China, causing instability in the region,” said Liu Pengyu, spokesperson of the Chinese embassy in the US.
Additional reporting by Kathrin Hille