A symbolic battle over flags on a disputed reef has reignited tensions between China and the Philippines, exposing the challenges to achieving maritime stability even as Beijing pledges to complete a long-delayed Code of Conduct aimed at preventing conflict in the South China Sea. Two weeks after Chinese coastguard personnel posed with their national flag on Sandy Cay – asserting “indisputable sovereignty” over the reef, which it refers to as Tiexian Jiao – Philippine navy, coastguard and police units mounted a counter-mission on Sunday, unfurling their own flags on three cays that form part of the feature. The Philippine team, using four motorised rubber boats, disembarked at Pag-asa Cay 1, Cay 2 and Cay 3 before sunrise. Their success was evidence that China’s earlier claims of control were misleading, according to Commodore Jay Tarriela, spokesman for the Philippine Coast Guard on South China Sea issues. “This is clear evidence that China’s narrative is only intended to counter our factual narrative that we can actually go to these cays,” Tarriela said in a radio interview on Monday. China has not disclosed precisely when its flag-raising operation took place, but state television and the Global Times have aired footage showing Chinese personnel planting the national flag on Sandy Cay. Sandy Cay is made up of several reef platforms that remain above water even at high tide, located just 1.5 nautical miles northwest of Philippine-occupied Thitu Island and 9.3 nautical miles northeast of Subi Reef, where China has constructed an artificial military island. In a statement quoted by Global Times, China Coast Guard spokesman Liu Dejun insisted: “The China Coast Guard will continue to carry out rights protection and law enforcement activities in the waters under China’s jurisdiction in accordance with the law and resolutely safeguard the country’s territorial sovereignty and maritime rights and interests.” Manila pushes back Given the gravity of China’s move, Philippine officials made clear they would not let the matter slide. Jonathan Malaya, assistant director general of the National Security Council, on Monday publicly reminded Beijing of its commitment under the 2002 Declaration on the Conduct (DoC) of Parties in the South China Sea, which states that no new occupation of previously unoccupied features should occur. “We urge the People’s Republic of China and the Chinese Coast Guard to maintain the status quo in the West Philippine Sea, consistent again with the 2002 Declaration on the Conduct, which they themselves are adhered to, which they themselves continue to refer to in each and every statement issued by the Chinese Foreign Ministry,” Malaya said. Analysts told This Week in Asia that China’s eagerness to control Sandy Cay forms part of a broader strategy. Retired Supreme Court justice Antonio Carpio said the flag incident “is part of China’s creeping invasion of the South China Sea to make the 10-dash line its national boundary”. A 2016 arbitral ruling by the International Tribunal on the Law of the Sea had declared China’s Nine-Dash Line as void and without legal basis under the United Nations Convention on the Law of the Sea (Unclos) which superseded all historical claims. Beijing rejected the decision but has since shifted to a 10-dash line formulation. Carpio, a fierce advocate for the West Philippine Sea (WPS) – or that portion of the South China Sea that Manila considers its maritime territory – said that “planting flags are for optics only. At this time such acts do not improve the legal position of a claimant state” like China. He said the 2016 arbitral ruling confirmed that features like Pag-asa are entitled to a territorial sea. He explained that the tribunal had specifically considered whether Pag-asa’s territorial sea extended to include Subi Reef, and concluded that it did, although it did not rule on which state holds sovereignty over Pag-asa. “Sandy Cay belongs to the Philippines because Sandy Cay emerged from the territorial sea of Pag-asa over which the Philippines has sovereignty,” Carpio said. Code of Conduct tensions The flag confrontation occurred shortly after China and the Association of Southeast Asian Nations (Asean) reaffirmed their commitment to finalising a Code of Conduct (CoC) for the South China Sea by 2026. The pledge was made during negotiations held in Manila from April 9 to 11. However, Matteo Piasentini, a fellow at the Honolulu-based Pacific Forum and a lecturer at the University of the Philippines, said China’s flag-raising was no surprise. He expressed the belief that it was intended “to signal that entering such negotiations is not tantamount to acquiescence to other countries’ claims over disputed features.” However, Manila’s counter-flag unfurling means that China “won’t be able to claim that the Philippines has tacitly acquiesced to its displays of sovereignty over the features,” he said. He said Manila’s bold action, carried out in full view of Chinese vessels, had both symbolic and legal significance. Symbolically, he said, the Philippines was signalling its determination to maintain its sovereign claims over the features. “Legally speaking, this is to be considered as a challenge to another country’s display of authority over a small portion of territory. By doing so, the Philippines aims at neutralising any Chinese sovereignty claims over the disputed areas,” Piasentini told This Week in Asia. He also noted that Sandy Cay’s elevation status under Unclos – as a rock capable of generating a territorial sea – added strategic weight. “China occupies Subi and the Philippines Thitu, which are nearby features, so of course controlling another feature improves a country’s position in the sea,” Piasentini said. Strategic containment Beyond symbolic gestures, experts warn of a broader Chinese strategy to consolidate control. For Chester Cabalza, founding president of the International Development and Security Cooperation think tank in Manila, Sandy Cay represents merely one step towards Beijing’s ultimate goal – containing Thitu Island, the Philippines’ largest and most important outpost in the Spratlys. “This quiet encirclement and blame game of China against the Philippines in the West Philippine Sea is an obvious containment of China,” Cabalza said. Manila’s flag-raising operation, he added, was a necessary act of defence. “Given the expansionist ambition of China to possess all the maritime claims in the South China Sea, it will push for what it wants to pursue China’s grand strategy,” Cabalza said. Manuel Mogato, a Pulitzer Prize-winning journalist who has covered the South China Sea dispute for more than 20 years, said China cannot occupy or build on Sandy Cay while it is pushing to complete a Code of Conduct with Asean. Doing so would violate the 2002 Declaration on the Conduct of Parties in the South China Sea, which China signed with Asean, he told This Week in Asia.