Foreign Relations & International Law

Water Wars: Two Collisions Near Second Thomas Shoal as Territorial Dispute Escalates

Teresa Chen, Alana Nance
Friday, October 27, 2023, 2:31 PM
Maritime incidents escalate in South China Sea; Biden administration conducts Indo-Pacific diplomacy; Philippines threatens another international arbitration; and more.
The Philippine Navy BRP Antonio Luna steams in formation with the USS Dewey and the Royal Navy HMS Spey during a Maritime Training Activity. (U.S. Navy photo by Petty Officer 1st Class Greg Johnson,; Public Domain)

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String of Maritime Incidents in Disputed South China Sea

Philippine Coast Guard Severs China’s Floating Barrier 

Late last month, China’s Coast Guard installed a floating barrier to disrupt navigation near the disputed Scarborough Shoal (China: Huangyan Dao; Philippines: Panatag Shoal). Although the 2016 South China Sea Arbitration rejected China’s maritime claim to the shoal in favor of the Philippines’s competing claim, China has rejected the arbitral ruling and preserved a continual coast guard presence around the strategically important shoal since China took control of it following a maritime standoff with the Philippines in 2012. 

The Philippines “strongly condemn[ed]” the placement of the barrier, claiming that it prevents Filipino fishing vessels from entering waters surrounding the shoal. On Sept. 26, the Philippine Coast Guard removed the barrier, calling it a “hazard to navigation” and “a clear violation of international law” that hindered the livelihood of Filipino fishermen within an “integral part of the Philippine national territory.” A video posted on social media by Philippine Coast Guard Commodore Jay Tarriela shows a Philippine Coast Guard diver cutting through an underwater rope that held the barrier in place. After the rope was cut, the Chinese Coast Guard reportedly removed the adrift barrier

During a press conference on Sept. 26, a Chinese Foreign Ministry spokesperson, Wang Wenbin, cautioned “the Philippines not to make provocation or stir up trouble.” The Chinese Coast Guard subsequently claimed that it had removed the barrier voluntarily and dismissed the “so-called dismantling of the Chinese barrier” as “a complete fabrication of facts and a self-induced drama directed by the Philippines.” In a statement on Sept. 27, Wang asserted that Scarborough Shoal is Chinese territory and called the Philippines’s alleged actions “purely a farce for its own amusement.”

On Sept. 28, Lindsey Ford, U.S. deputy assistant secretary of defense for South and Southeast Asia, commended the Philippines for removing the barrier, calling the action “a bold step in defending their own sovereignty.”

Philippine President Ferdinand Marcos Jr. said on Sept. 29 that the Philippines does not want a confrontation with China but will “continue defending the maritime territory of the Philippines and the rights of our fishermen, who have been fishing in those areas for hundreds of years.” The same day, Philippine Defense Secretary Gilberto Teodoro Jr. told CNN that China is acting like a “bully” in the South China Sea. He claimed that the Philippines’s refusal to back down in the face of China’s intrusions on its exclusive economic zone (EEZ) constitutes a fight for the country’s very existence. He predicted that China will not stop intruding on sovereign rights until it controls the whole South China Sea.

The Philippine Coast Guard encouraged Filipino fishermen to continue operating at Scarborough Shoal and other disputed sites in the South China Sea, notwithstanding China’s presence. 

Filipino Fishermen Killed in Collision Near Disputed Shoal

Only days after the barrier incident unfolded, three Filipino fishermen were killed on Oct. 2 when their fishing boat was hit by another vessel near the disputed Scarborough Shoal. President Marcos called on the public to “refrain from engaging in speculation” during the Philippine Coast Guard’s investigation of the incident but promised that those responsible for the maritime incident would be held accountable. The Coast Guard reported two days later that a Marshall Islands-flagged oil tanker, the Pacific Anna, is suspected of having been involved in what the Coast Guard called an “accidental collision.” The Coast Guard said it would attempt to contact the tanker, which at the time was en route to Singapore. The Pacific Anna’s owner had not yet been identified.

Near Miss as Chinese Coast Guard Interferes Again With Sierra Madre Resupply

On Oct. 4, a Chinese Coast Guard vessel and a Philippine Coast Guard vessel came within three feet of colliding when the Chinese vessel attempted to block the Philippine vessel from carrying out a resupply mission to the BRP Sierra Madre. The BRP Sierra Madre is a World War II-era vessel that the Philippines intentionally grounded on Second Thomas Shoal (Philippines: Ayungin Shoal; China: Ren’ai Jiao; Taiwan: Ren’ai Ansha; Vietnam: Bãi Cỏ Mây) in 1999 and aboard which it has since maintained a garrison of military personnel in order to reinforce the Philippines’s claim of sovereignty over the feature, which China contests. As documented previously in Lawfare, Second Thomas Shoal has been a site of escalating tensions between China and the Philippines in recent months.

The Philippine Coast Guard alleged that, during this recent incident, four Chinese Coast Guard ships and five maritime militia ships attempted to block the Philippine vessels from reaching the BRP Sierra Madre. The BBC was aboard one of the Philippine vessels at the time of the incident and confirmed the attempted blocking. Ultimately, two smaller Philippine supply boats made it through the Chinese blockade and successfully resupplied the BRP Sierra Madre’s garrison, according to a Philippine government body.

A spokesperson for the Chinese Coast Guard alleged that the Philippine ships had entered the area without the Chinese government’s permission and asserted China’s “indisputable sovereignty” over Second Thomas Shoal and its adjacent waters. The following week, the Chinese Foreign Ministry remarked that Second Thomas Shoal “has never been the Philippines’ territory” and called the grounding of the BRP Sierra Madre a grave violation of China’s territorial sovereignty. 

Vessels From China and the Philippines Collide Near Second Thomas Shoal

On Oct. 22, regional tensions escalated further when a Philippine supply boat and a Chinese Coast Guard vessel collided near Second Thomas Shoal. A Philippine Coast Guard ship and a Chinese maritime militia vessel are also reported to have collided during the same encounter. The incidents occurred during what appears to be the second attempt this month by the Chinese Coast Guard to prevent Philippine vessels from reaching the BRP Sierra Madre. No injuries have been reported as a result of the collision. The Armed Forces of the Philippines posted videos of both incidents on social media.

China and the Philippines have traded accusations over the collisions. Philippine authorities claimed that the Chinese vessels engaged in “dangerous blocking maneuvers” that resulted in collisions as Philippine vessels attempted to carry supplies to the grounded warship’s garrison. The Chinese Coast Guard accused the Philippines of violating international law, trespassing into Chinese waters, and threatening the safety of navigation of Chinese vessels—prompting the Coast Guard to intercept the Philippine ships and resulting in a “minor collision.” The Philippine Foreign Ministry summoned the Chinese ambassador to “condemn the reckless and illegal act of the Chinese government.” Philippine President Marcos has ordered an investigation of the collisions and reportedly plans to raise the issue of China’s dangerous maneuvers in code of conduct discussions between China and the Association of Southeast Asian Nations (ASEAN).

In response to the incident, the U.S. Department of State released a statement condemning the Chinese Coast Guard’s “dangerous maneuvers,” which “violated international law by intentionally interfering with the Philippine vessels’ exercise of high seas freedom of navigation.” It also accused China of undermining regional stability by interfering with supply lines to the Philippines’s “longstanding outpost,” the BRP Sierra Madre. The State Department asserted that Second Thomas Shoal is “well within the Philippine exclusive economic zone and on the Philippine continental shelf,” citing the 2016 International Tribunal’s “legally binding” decision, which found no legal basis for China’s maritime claim to the feature. The State Department also reaffirmed the U.S.’s commitment to defend the Philippines against armed attacks anywhere in the South China Sea pursuant to Article IV of the 1951 U.S.-Philippines Mutual Defense Treaty.

On Oct. 23, a China Foreign Ministry spokesperson, Mao Ning, told reporters that the U.S. had issued the statement “in violation of international law, groundlessly attacking and accusing China’s legitimate rights and law enforcement actions.” She reiterated China’s claim that it has always had control over Second Thomas Shoal.

Philippines Contemplating International Legal Action Over Coral Reef Destruction

Despite Beijing’s refusal to abide by the 2016 South China Sea arbitral ruling (which largely upheld the Philippines’s maritime territorial claims over China’s “nine-dash line”), the Philippines is reportedly considering filing a second legal action against China before the Permanent Court of Arbitration in the Hague to address environmental destruction within its internationally recognized EEZ.

The Philippine Coast Guard released video footage last month showing large areas of bleached, cleaned, and crushed corals that had been dumped in the seabed near Iroquois Reef (China: Houteng Jiao; Philippines: Del Pilar Reef/Rozul Reef; Vietnam: Đá Khúc Giác) and Sabina Shoal (China: Xianbin Jiao; Taiwan: Xianbin Ansha; Vietnam: Bai Sa Bin; Philippines: Escoda Shoal), two features within the Philippines’s EEZ. According to the Philippine Coast Guard, 33 Chinese vessels had been moored at Iroquois Reef and engaged in harvesting coral in August and September. The Philippines blamed China’s maritime militia for the environmental damage, alleging “indiscriminate illegal and destructive fishing activities.”

China denied the accusation, calling the allegations “false and groundless.” Foreign Ministry spokesperson Mao Ning called on Philippine authorities “not to utilize fabricated information to stage a political farce.”

Philippine Navy Engages With Partner Nations

Philippine Navy Conducts Joint Maritime Operations With Canada

The Philippine Navy conducted joint maritime operations with the Canadian Navy in the South China Sea on Sept. 21. The Philippine Navy frigate BRP Antonio Luna (FF-151) and the Royal Canadian Navy frigate HMCS Ottawa (FFH 341) conducted a three-hour joint sail in the West Philippine Sea, an area of the South China Sea located within the Philippines EEZ but where China attempts to enforce its own sovereignty. Canada is the latest among several countries to begin or express interest in joint South China Sea patrols with the Philippines, an effort directed at countering China’s aggressive maritime claims in the region. Only last month, Australia pledged to begin its own joint patrols with the Philippines.

Philippines, U.S., and Partner Nations Team Up for Maritime Training Exercise

In October, the armed forces of the U.S. and the Philippines teamed up for Maritime Training Activity Sama Sama 2023 in Manila. The seventh and largest yet iteration of the multilateral training exercise also included participants from six other partner nations and featured a land phase, anti-submarine drills, surface warfare drills, and air warfare drills.

White House Hosts Second U.S.-Pacific Islands Forum Summit

In late September, President Biden hosted Pacific Islands leaders at the White House for the second U.S.-Pacific Island Forum Summit. Biden hinted at a plan for an additional $200 million in funding for initiatives in the Pacific Islands region including mitigating climate change, improving public health and economic development, and policing illegal fishing. He also announced the U.S.’s diplomatic recognition of two additional Pacific Island nations, the Cook Islands and Niue. The leaders who attended the summit issued a statement reaffirming the U.S.-Pacific Partnership and committing to biennial summits, with the next set to take place in 2025.

Notably absent from the summit was President Manasseh Sogavare of the Solomon Islands. Although he attended the U.N. General Assembly in New York the previous week (where he praised China’s development cooperation with the Solomon Islands), he declined to attend the White House summit because he claimed that he did not want to listen to a “lecture.” The Biden administration expressed disappointment at Sogavare’s decision to skip the summit.

​​U.S. Committed to Diplomatic Initiatives in the Indo-Pacific Region 

November Xi-Biden Meeting in the Works

In early October, news outlets reported that the United States and China were working toward a meeting between President Biden and President Xi Jinping in November. The two leaders would likely speak sometime during the two-day Asia Pacific Economic Cooperation (APEC) summit in San Francisco, which is scheduled to begin on Nov. 16. Though China is still in conversation with the United States about who will represent China at the APEC summit, U.S. officials told the Washington Post that the chances of a summit between the two leaders were “pretty firm.” 

Since the alleged Chinese spy balloon incident earlier this year, the United States and China have attempted to stabilize volatile bilateral relations. This has included a number of trips taken by U.S. Cabinet-level officials to China: A trip to Beijing by U.S. Secretary of State Antony Blinken in June was followed by visits to the country from Treasury Secretary Janet Yellen, Commerce Secretary Gina Raimondo, and Climate Czar John Kerry later in the summer. In early September, U.S. National Security Adviser Jake Sullivan met with Chinese Foreign Minister Wang Yi in Malta to discuss the possibility of a Xi-Biden meeting. China and the United States also recently announced the establishment of working groups to discuss economic and financial issues held by senior officials, an indicator of improving relations between the two countries. According to a press release by the U.S. Treasury Department, it will lead the Economic Working Group with China’s Finance Ministry, and it will lead the Financial Working Group with the People’s Bank of China. The two groups will hold meetings regularly, and will report to Secretary Yellen and Chinese Vice Premier He Lifeng.

Additional Updates on U.S. Diplomatic Initiatives in the Indo-Pacific Region 

  • From Oct. 15 to Oct. 24, a U.S. delegation traveled to Kuala Lumpur for the sixth negotiating round of the Indo-Pacific Economic Framework for Prosperity (IPEF). The U.S. interagency delegation included representatives from the U.S. Department of Commerce and the Office of the U.S. Trade Representative and was co-led by Sharon H. Yuan, U.S. Department of Commerce counselor, and Sarah Ellerman, assistant U.S. trade representative for Southeast Asia and the Pacific. The sixth negotiating round focused on making progress toward outcomes under Pillars I (Trade), III (Clean Economy), and IV (Fair Economy).
  • The Department of Defense released its 2023 China Military Power Report, which “charts the current course of the PRC’s national economic and military strategies, and offers insight into the [Chinese military’s] strategy.” Discussing the report, Ely S. Ratner, assistant secretary of defense for Indo-Pacific security affairs, said the United States is “clear eyed about the challenges posed by the [China’s People’s Liberation Army] …. But at the same time … [the United States is] doing more than ever—together with our allies and partners—to … advanc[e] a common vision for regional peace and stability.”
  • After the U.S. Marine Corps completed a joint exercise in Hawaii in September with the U.S. Pacific Fleet and the Hawaii Air National Guard, it began a rotational force deployment to Southeast Asia on Sept. 26. The Marine Rotational Force-Southeast Asia (MRF-SEA) will conduct a series of “back-to-back exercises and security cooperation engagements with allies and partners in Southeast Asia, including the Philippine Marine Corps, the Royal Malaysian Navy (RMN) and the Indonesian Marine Corps.”
  • In early October, U.S. Secretary of Defense Lloyd Austin said the United States was firmly committed to defending Japan, including the Senkaku Islands and other territories, as encapsulated by Article V of the Japan-U.S. Security Treaty. As a signal of such commitment, the United States, Japan, and South Korea held a joint drill in the East China Sea this month. In total, the three countries deployed seven vessels, including the U.S. Navy’s USS Ronald Reagan, a Japanese Maritime Self-Defense Force Hyuga-class destroyer, and South Korean navy destroyers. Following the trilateral drill, the USS Ronald Reagan visited the South Korean port of Busan. This was the second U.S. nuclear-powered aircraft carrier to visit South Korea since March.

Taiwan Unveils First Domestically Made Submarine

On Sept. 28, Taiwan unveiled the island’s first domestically made submarine for testing in the port city of Kaohsiung. If successful in its testing, the submarine would be a major milestone in Taiwan’s defense strategy against an increasingly aggressive China. Named the “Haikun”—a mythical fish that can also fly in classical Chinese literature—and the “Narwhal” in English, the submarine cost Taiwan US$1.54 billion and is powered by diesel and electricity. It will undergo harbor and ocean-faring tests, before being delivered to the Taiwanese Navy by the end of 2024.

At the submarine’s launch ceremony, Taiwanese President Tsai Ing-wen stated: “In the past, a domestic-made submarine was considered impossible, but today a submarine designed and built by our countrymen is in front of you. … Building a submarine is the concrete realization of our resolution to protect our country. Submarines are an important piece of equipment for the Taiwan navy to develop asymmetric combat power in terms of strategy and tactics.” The submarine launch was a personal victory for President Tsai, who created the defense policy to build domestic submarines when she took office in 2016, and who viewed the indigenous submarine project as a “top priority” for her administration.

If successful, the indigenous submarines will be important in defending the first island chain in the Bashi channel, which separates Taiwan from the Philippines. In an internal briefing, Adm. Huang Shu-kuang, an adviser of Taiwan’s National Security Council, stated that Taiwan’s deployment of its submarines in the Bashi channel to protect against China’s military power would be strategic, given that the Chinese navy would likely “want to enter the area to the east of Taiwan” in an attempt to surround the island and limit the U.S.’s ability to intervene. Huang added that “because submarines can operate deep under water and are hard to detect, they have a better chance of getting close to (Chinese) aircraft carriers” and launching attacks from the first island chain. The submarines were also designed to be able to carry U.S.-made MK-48 torpedoes, which can target surface ships.

In response to Taiwan’s submarine launch, China’s Defense Ministry stated that the submarine’s construction was a sign that Taiwan was “heading down the path of its own destruction.” When asked about the submarine by reporters, a Chinese Defense Ministry spokesperson said that the submarine was “idiotic nonsense” and that “no amount of weapons [Taiwan] ... buys or makes can stop reunification with the motherland.”

In recent weeks, Beijing has ramped up its military presence around the island, with Taiwan raising concerns that the increased frequency of Chinese military activity was “getting out of hand.” U.S. military and intelligence officials have provided different predictions on the timing of a possible Chinese invasion of Taiwan. 

South Korea, Japan, and China Agree to Hold Trilateral Summit

Following the historic trilateral summit among the United States, South Korea, and Japan in August 2023 (previously covered in Lawfare), senior diplomats from South Korea, Japan, and China agreed in late September to revive this summit among the East Asian nations. South Korea’s Foreign Ministry said the country’s leaders would meet at the “earliest convenient time” and estimated that the summit would occur “in a couple of months.” South Korea is set to be the host for this year’s trilateral summit.

The three nations had agreed to hold annual summits to foster regional cooperation since 2008, but this goal failed to materialize: Meetings stalled because of bilateral tension and the coronavirus pandemic. There was a two-year hiatus from 2013 to 2015 because of strained bilateral relations between Japan and China, as well as between Japan and South Korea. The three nations also failed to meet in 2016 and 2017 because of tensions in all three of the bilateral relationships, along with then-South Korean President Park Geun-hye’s entanglement in a corruption and cronyism scandal which ultimately led to her impeachment and removal from office. The last trilateral summit was held in 2019.

The revival of the trilateral summit has been described as an attempt to mitigate China’s diplomatic concerns after South Korea and Japan agreed earlier this year to end all legal and diplomatic disputes over issues that stem from Japan’s occupation of Korea from 1910 to 1945. In describing the summit, Japanese Foreign Minister Yoko Kamikawa asserted that the three countries needed to restart conversations “as soon as possible” because “it is very valuable to discuss the various challenges the region faces.” Wang Wenbin, a Chinese Foreign Ministry spokesperson, echoed similar sentiments.


At the South China Morning Post, Richard Heydarian writes of the unexpected deterioration in relations between China and the Philippines. Citing the recent string of escalating incidents between the two countries and the Philippines’s expansion of military ties with the U.S., he asserts that the two sides “risk direct confrontation unless they proactively de-escalate tensions through a new modus vivendi in the South China Sea” and suggests “proactive, subtle diplomacy” to prevent the two nations from “sleepwalking into a devastating conflict.” He argues that the Philippines should provide China assurances against U.S. weaponization of new Enhanced Defense Cooperation Agreement (EDCA) bases in the Philippines, reconsider its threat to file a new international arbitration against China over destruction of coral reefs, and reject “growing suggestions” of adding areas in the Spratly Islands to the list of new EDCA bases. In return, China should stop interfering with the Philippines’s attempts to assert its presence in its own EEZ (notably Second Thomas Shoal), refrain from harassing Philippine fishermen, and negotiate “over a possible service contract deal in the Reed Bank,” where the Philippines hopes to exploit energy resources, in exchange for recognition of the Philippines’s sovereign rights to the area.

At a panel hosted by the U.S. Naval Institute, Rear Adm. Michael McDevitt highlighted divisions between the Chinese People’s Liberation Army Navy’s (PLAN’s) military and political leadership, which could create problems for the PLAN during wartime. McDevitt emphasized that the PLAN’s unique command system (which he describes as shared command between the co-equal ship’s captain and ship’s political officer) has never been tested in conflict and may prove to be a “potential weakness.” Nonetheless, McDevitt cites China’s Indian Ocean deployments and methodical approach to carrier aviation as signs of the PLAN’s effectiveness.

Samuel Ng at the Australian Institute of National Affairs argues that China’s August 2023 release of its new South China Sea map (asserting even greater territorial claims) has given Taiwan an opportunity to earn the favor of other countries in the South China Sea by renouncing its own “unrealistic territorial claims.” Ng argues that, although Taiwan does not support China’s territorial claims, Taiwan is nonetheless giving China tacit support for them by continuing to adhere to its own “unrealistic” and “identical” claims. He contends that China’s new map has given Taiwan an opportunity to strengthen its relations with its South China Sea neighbors, “increasing its credentials as a good international citizen worthy of greater diplomatic engagement,” by renouncing its own expansive claims and embracing its separate Taiwanese identity.

Also at the Australian Institute of National Affairs, Patrick Mendis and Antonina Luszczykiewicz write that a traditional U.S. Cold War containment policy will be ineffective against China’s “Blue Dragon” anti-containment strategy across four geographic frontiers: Taiwan and the Senkaku Islands; China’s artificial islands in the South China Sea; Sri Lanka and the Indian Ocean; and the Brahmaputra River basin and Mekong River in India and Southeast Asia. The authors suggest that U.S. military cooperation—through the Quadrilateral Security Dialogue (the Quad), AUKUS (the security partnership between the United States, Britain, and the U.S.), and defense treaties with countries like the Philippines and Vietnam—is “not a panacea” and will not, alone, achieve the U.S.’s goals. Rather, they argue, the U.S. should treat its “small” regional allies as friends and partners not only in military cooperation, but in the economic realm as well. They credit the Biden administration’s “charm offensive” aimed at the Pacific Islands forum as an example of nonmilitary engagement that will help the U.S. stay ahead of China. They also suggest that, with its increasingly centralized power, Beijing might be driven to overestimate its own military might and economic capacity and become “its own worst enemy.” The authors recommend that the U.S. pursue active partnerships with friends and allies while allowing Beijing to “make its own mistakes and miscalculations.”

At 9DASHLINE, Dylan Motin writes that under President Emmanuel Macron, France has given the Indo-Pacific a level of attention not present since the country’s 1954 withdrawal from Indochina. France released its first Indo-Pacific Strategy in 2018 and asserts itself as an Indo-Pacific power through “high-profile” naval deployments. France justifies this strategy as “commitment to stability, multilateralism, and a refusal of military blocs.” However, according to Motin, France’s strategy is really motivated by self-interest, “profoundly concerned with containing” China, and aligned with the U.S., despite the government's “official rhetoric of transcending great power competition.” Motin writes that China is “lucid about French intentions” and sees France “as an American wingman.”

And finally, at The Diplomat, Andrew Orchard writes about China’s latest provocation against Japan—the deployment of an oceanographic buoy, 10 meters in diameter, within the Japanese EEZ. Japan believes that the deployment of the buoy violates the U.N. Convention on the Law of the Sea (UNCLOS), because coastal states must consent before foreign nations may conduct maritime scientific research inside a country’s EEZ. Orchard argues that since China has done nothing to clarify the buoy deployment, its intrusion on Japan’s EEZ is an intentional attempt to assert its own claim that China’s EEZ extends beyond the median line.

Teresa Chen is a J.D. student at Harvard Law School. She holds a bachelor’s degree in Global Affairs from Yale University.
Alana Nance is a J.D. student at Harvard Law School. She holds a bachelor’s degree in Chinese from the U.S. Naval Academy and served as an officer in the U.S. Marine Corps.

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