A tiny sandbar in the disputed South China Sea has become the latest flashpoint in tensions between China and the Philippines, with each side displaying its flag to reinforce competing claims on the island.
Earlier this month, members of the Chinese Coast Guard landed on the disputed reef, Sandy Cay, unfurled a flag and “exercised sovereign jurisdiction,” Chinese state media reported on Thursday.
They left the island by Sunday, when the Philippines deployed its own personnel to the sandbar. Hours later, Beijing called the act an “illegal boarding,” saying it had “indisputable sovereignty” over the Spratly Islands, a chain of dozens of slivers of land, including Sandy Cay, in the South China Sea, and its surrounding waters.
The standoff comes days after the United States and the Philippines began their annual joint military drills in the Philippines, which China has criticized as undermining regional stability. The United States is a treaty ally of the Philippines and has pledged to come to the aid of Manila in the event of an attack.
China’s expansive territorial claims in the South China Sea have flared tensions in the region for years. It has built up a large military presence in the Spratlys, setting up a military base on reclaimed land around Subi Reef, which is near Thitu Island, the Philippines’ most important military outpost in the Spratlys.
Some observers said China might be trying to assert control of Sandy Cay — which covers an area of 200 square meters, or about 2,150 square feet — to legitimize its claim on Subi Reef, the naturally occurring parts of which are submerged during high tide.
“Even if they created an artificial island, there’s no territorial sea,” said Antonio Carpio, a former Supreme Court justice who helped the Philippines win a landmark international ruling against China over its claims in the South China Sea. “The only way they can legalize that is to get Sandy Cay.”
Euan Graham, a senior analyst at the Australian Strategic Policy Institute, said the latest development reflected a shift in China’s approach in the South China Sea.
“They’re not piling on giant slabs of concrete or pouring on the PLA,” Mr. Graham said, referring to the People’s Liberation Army of China. “They’re doing a flag waving ceremony, hopping off and claiming sovereignty and testing the waters to see what happens. The interesting part is that the Philippines went straight in and effectively copied the same modus operandi.”
He added: “The key question is, what’s the U.S. attitude? Will they back their ally if it gets more heated, or will they effectively say, ‘Well, no, we’re not going to go to war over a silly piece of sand.’”
On Monday morning, Jonathan Malaya, the assistant director general of the Philippines’ National Security Council, pushed back on China’s claim that Beijing had seized the reef and urged it to “act with restraint and not increase tensions” in the South China Sea.
“It is not to the benefit of any nation if these things are happening, nor is it to the benefit of any nation if such irresponsible announcements and statements are released to the public and to the world,” he told reporters.
Beijing claims about 90 percent of the South China Sea, parts of which are also claimed by Vietnam, Malaysia, Brunei, Indonesia and the Philippines. Manila has been at the forefront of the territorial fight, saying that Chinese ships have been blocking access to fishing sites as well as oil and gas deposits in the waters that are in its exclusive economic zone.
Those tensions have escalated dramatically in recent years, raising the risk that Washington could be drawn into a conflict.
Both the Philippines and China have published photographs of their own flags being displayed on the reefs. The Chinese state broadcaster CCTV published a photograph of four people standing on the uninhabited reef.
Jay Tarriela, a spokesman for the Philippines Coast Guard, told reporters that Manila had deployed officers to check whether the Chinese government had installed any infrastructure or monitoring devices on Sandy Cay but found nothing. But he added that a Chinese Coast Guard vessel and seven China maritime militia vessels remained near the island.
