The Philippines denounced Beijing’s latest aggressive activities in the South China Sea that include China raising its national flag on Sandy Cay and propagating false claims about the stretch of three uninhabited sandbars that the Philippines calls Pag-asa Cay 2.
“The alleged seizure of Pag-asa Cay 2, an integral part of the Philippine national territory in the West Philippine Sea, was a clear example of the disinformation activities of the Chinese government, where it made it appear that China has effective control of the cay by displaying its flag and conducting waste collection,” the Philippines’ National Maritime Council (NMC) stated.
In late April 2025, a day after China raised its flag, the Philippine Coast Guard released a photo of its personnel raising the nation’s flag on the cay, asserting the Philippines’ sovereignty. The sandbars are near a key Philippine military outpost in the disputed Spratly Islands.
The National Task Force for the West Philippine Sea said it conducted an operation among the Coast Guard, Navy and maritime police to reinforce “Philippine authorities’ routine and lawful exercise of maritime domain awareness and jurisdiction over the West Philippine Sea,” which is what Manila calls the portion of the South China Sea within its exclusive economic zone (EEZ).
In early May, the Philippines also criticized the Chinese Communist Party’s (CCP) attempts to spread manipulated information about the sandbars allegedly being under China’s control, according to The Manila Times newspaper.
“The Philippines is firm in protecting its vast maritime domain and is unwavering in fighting false allegations that detract from the country’s lawful exercise of its sovereignty, sovereign rights and jurisdiction,” the NMC said.
Before planting its flag, Beijing released a specious report blaming Manila for coral damage at Sandy Cay.
The NMC has accused China of degrading the environment surrounding Pag-asa Island and its cays. The council contends that continual illegal swarming by Chinese vessels in the area and China’s massive artificial island-building on Subi Reef, which the Philippines calls Zamora Reef, caused environmental damage, the Philippine News Agency reported.
“The Philippines will consistently pursue peaceful means for resolving disputes and constructive approaches to managing differences, while also continuing its lawful and routine activities in the West Philippine Sea, consistent with its maritime entitlements under international law,” the NMC said.
China claims most of the resource-rich South China Sea, including the Spratly Islands and Sandy Cay, despite an international tribunal’s 2016 ruling rejecting Beijing’s contentions and siding with the Philippines, which filed the complaint under the United Nations Convention on the Law of the Sea (UNCLOS). Brunei, Malaysia and Vietnam also claim portions of the sea, a vital global trade route.
Sandy Cay is near Thitu Island, Manila’s largest and most strategic outpost in the Spratlys.
“If the Chinese were to build certain military infrastructure there, they could closely monitor activity on nearby Philippine islands,” Abdul Rahman Yaacob, a research fellow in the Southeast Asia program at the Australia-based Lowy Institute, told the CNA news site.
Under UNCLOS, Sandy Cay is classified as a rock permanently underwater and therefore entitled to a 12-nautical-mile territorial sea from its shore, analysts say. In addition, the cay is about 2 nautical miles from Pag-asa Island, the main island in the Kalayaan municipality of the Philippines’ Palawan province, which means it is within the island’s EEZ.
China broadcast video of its flag planting, showing four uniformed personnel in black combat gear holding the flag after arriving in a dinghy.
Since the 1990s, Beijing has typically used Chinese fishermen, maritime militia and civilian groups to plant flags on disputed reefs, rocks and islands in the sea.
Analysts said Beijing’s actions, which reignited tensions over Sandy Cay, were an attempt to save face domestically amid mounting external pressure.
China’s expanding aggression in the South China Sea was probably timed to coincide with the multinational Balikatan military exercise hosted by the Philippines and the United States, and the upcoming midterm elections in the Philippines, Yaacob said.
“It’s a warning for the Philippines [against] further developing closer defense relations with the U.S.,” he told CNA. “It’s a signal to say, look, this is what we can do to counter you.”
Analysts also contend that Beijing’s April 2025 environmental report is part of its strategy to control more of the South China Sea.
Historically, China’s artificial-island building has caused about two-thirds of the damage to marine habitats in the sea, according to the Asia Maritime Transparency Initiative (AMTI). Through its dredge-and-fill construction, China has buried more than 4,600 acres (about 19 square kilometers) of coral reef since 2013, AMTI reported in January 2025.
Those activities “cause irreparable and long-term changes to the overall structure and health of the reef,” the report said.
China’s latest activities at Sandy Cay are likely designed to incrementally expand its presence in the Philippines’ EEZ, according to Don McLain Gill, a Manila-based analyst and international studies professor at De La Salle University.
The activities are part of Beijing’s “salami slicing” approach to maritime claims, he wrote in April 2025 for ThinkChina, a Singapore-based magazine.
For example, China claimed its construction of artificial islands on such features as Fiery Cross Reef in the Spratlys, which started in 2014, was for civilian purposes. However, Beijing built military structures including airstrips, radar installations and missile launchers.
In recent years, China has also used its coast guard and maritime militia to assert its excessive claims in the South China Sea.
In January 2025, for example, a China Coast Guard vessel blocked a Philippine scientific mission to Sandy Cay. Such activities may be due to the CCP’s awareness that “whoever possessed the feature could potentially lay jurisdictional claim to Subi Reef, a naturally submerged feature at high tide, over which China has built a large-scale base on reclaimed land, including an airstrip and port,” Euan Graham, a senior analyst at the Australian Strategic Policy Institute, wrote for the think tank’s publication, The Strategist.
Chinese vessels also have rammed and fired high-pressure water cannons at Philippine boats.
To counter China’s aggression and defend its territorial claims, the Philippines must maintain its presence in the strategic waterway, including with recurring patrols with defense partners, Gill wrote.
