Philippines warns China over potential act of war as tensions rise in South China Sea

If a Filipino citizen were killed in a confrontation with the Chinese coastguard, it would be very close to an act of war, the president of the Philippines has warned.

Asked at the opening of the Shangri-La Dialogue defence summit in Singapore whether China would be crossing a “red line” if one of its coastguard ships killed a Filipino during a confrontation, Ferdinand Marcos, the Philippine president, replied it “almost certainly” would.

Clashes between Filipino and Chinese coastguard vessels in the contested South China Sea have intensified during the past year as Beijing steps up its claims over shoals and reefs in waters that Manila says are legally within its 200-mile exclusive economic zone.

Chinese vessels have accelerated so-called grey-zone activities, including shadowing, bumping, harassing, and swarming Filipino supply and patrol ships, as well as using high-powered water cannons to block their passage.

Close to an act of war

“If a Filipino citizen is killed by a wilful act, that is very close to what we define as an act of war, and therefore we will respond accordingly, and our treaty partners, I believe, also hold that same standard,” he said. “We would have crossed the Rubicon.”

Mr Marcos’s remarks came just hours after the US and Chinese defence chiefs shared their first handshake at Asia’s top security summit – a symbolic gesture that many hope will curb the risk of conflict in the Indo-Pacific’s many hotspots.

The annual summit, which draws together hundreds of senior defence and intelligence officials for high-level talks every June, has evolved into a gauge of diplomatic and military relations between Washington and Beijing since its launch over 20 years ago.

Lloyd Austin, the US defence secretary, met Admiral Dong Jun, his Chinese counterpart, for the first time just days after Beijing sparked alarm with military drills to “punish” perceived separatists and encircle democratic Taiwan, testing its ability to seize power there.

Few believe the meeting will change the course of potential conflict, but the fact that it even happened was progress for the rival superpowers, who are trying to restore military communications channels that broke down as ties frayed in 2022.

Mr Austin was snubbed last year by Mr Dong’s predecessor, Li Shangfu. This year, however, he had a 75-minute face-to-face conversation that was described by Senior Col Wu Qian,the Chinese military spokesman, as “positive, practical, and constructive”.

The two countries “agreed that a stable US-China military-to-military relationship is important,” Col Wu said, despite confronting each other over contentious issues like Taiwan and the South China Sea.

“The secretary expressed concern about recent provocative PLA activity around the Taiwan Strait, and he reiterated that the PRC should not use Taiwan’s political transition — part of a normal, routine democratic process — as a pretext for coercive measures,” Air Force Maj Gen Patrick Ryder said after the meeting.

In his speech, Mr Austin sought to allay fears that the wars in Ukraine and Gaza have taken attention away from the Indo-Pacific.

“Despite these historic clashes in Europe and the Middle East, the Indo-Pacific has remained our priority theatre of operations,” he said. “Let me be clear: The United States can be secure only if Asia is secure.”

It is the spiking tension in the South China Sea that will receive top billing this weekend, and which many believe has a higher chance of tipping into conflict – even accidentally – in the near term.

‘Filipinos do not yield’

Mr Marcos delivered a closely watched keynote speech on Friday evening and, as expected, underscored his nation’s determination to defend its sovereignty in the face of China’s aggressive territorial claims over maritime features near the Philippine coastline.

Addressing senior defence officials from more than 40 countries, including Mr Austin and Mr Dong, he denounced what he described as “illegal, coercive, aggressive and deceptive actions” being taken in the disputed South China Sea – a clear censure of Beijing without explicitly naming it.

Such actions “continue to violate our sovereignty, sovereign rights, and jurisdiction,” he said, adding: “Filipinos do not yield.”

But he also had firm words for treaty ally, the United States, underscoring that competition between Washington and Beijing was destabilising the Indo-Pacific region.

“Their rivalry is constraining the strategic choices of regional states. Their contest is exacerbating flashpoints and has created new security dilemmas,” he said, urging both countries to better manage their relations.

Mr Marcos has boosted the Philippines’ security relationship with Washington and taken a firmer line with China since entering office.

In recent months, there have been frequent flare-ups between Manila and Beijing over disputed reefs, atolls, and other features of the South China Sea.

Many of the tense run-ins have been near the Scarborough Shoal, a rich fishing ground within the Philippines’ exclusive economic zone (EEZ), and the Second Thomas Shoal, where a grounded and rusting warship, the Sierra Madre, serves as a Philippine military outpost to stake Manila’s claims.

This week, Mr Marcos described new rules outlined by China’s coastguard, granting it the right to detain foreigners accused of trespassing into waters claimed by Beijing, as “worrisome”.

China, however, argues it is the Philippines that is deliberately stoking strife.

Beijing asserts historical rights to much of the resource-rich South China Sea, which not only contains plentiful deposits of fossil fuels but today facilitates about $3.4 trillion in annual ship-borne trade.

An international tribunal in The Hague dismissed China’s assertions in 2016 as having no legal basis, but China rejected this ruling and has continued to militarise islands and atolls while denying access to disputed waters to rival Southeast Asian claimants.

Risk of major conflict

The rising skirmishes between Philippine and Chinese vessels in the South China Sea could spark a major conflict at “any time,” Jose Manuel Romualdez, the Philippine ambassador to the US, warned in a Nikkei interview late last year.

Many foreign policy experts agree that this disputed waterway is currently riper for a clash than the Taiwan Strait.

“I have thought for some time that the most dangerous near-term flashpoint in the Indo-Pacific is Second Thomas Shoal, not Taiwan,” said Bonnie Glaser, managing director of the Indo-Pacific Programme at the German Marshall Fund of the United States.

“I also expect that the US and other like-minded countries will echo [Mr Marcos’s] messages about the rule of law and the need to settle disputes peacefully.”

The stakes are high for Washington, which is bound to respond to any military attack on the Philippines by the 1951 Mutual Defence Treaty (MDT).

However, the Cold War-era agreement did not foresee the kinds of coercive grey-zone tactics used by Beijing to change the status quo without resorting to lethal force, and the Biden administration has not fully spelled out what types of Chinese behaviour could invoke a US reaction.

In April, Mr Marcos signalled the death of any Filipino serviceman because of “an attack or aggressive action by another foreign power” in the South China Sea would be enough to activate the treaty.

Such a scenario could have dire consequences, Commodore Jay Tarriela, spokesman for the Philippine Coastguard, told The Telegraph last month.

“I’m very sad to say this, but there will be war and the MDT would invoke the inclusion of the United States in that kinetic conflict,” he said.

But defence analysts like Dr Collin Koh, a senior fellow at Singapore’s S. Rajaratnam School of International Studies, argue the trigger and nature of possible US intervention in such circumstances is much less clear-cut.

“It is probably in the best interests of the US, China, and the Philippines that the MDT remains strategically ambiguous,” he said.

Strategic ambiguity

While there was a risk of “inadvertent or accidental” clashes, Beijing would likely back down from actual conflict in the South China Sea, he said.

“I believe that China is likely to stay laser-focused on Taiwan and not allow other regional flashpoints to serve as a distraction,” said Dr Koh.

Both Lloyd Austin and Dong Jun are expected during their own speeches this weekend to lay out their nations’ tough stances on the future of Taiwan, the South China Sea, and repeated territorial stand-offs between Beijing and Tokyo over the contested Senkaku Islands.

Chinese coastguard ships have been spotted in waters around the uninhabited Japanese-controlled island chain for a record 158 consecutive days, Tokyo revealed on Monday.

An incident there could again raise the prospect of regional conflict as the US also has a mutual defence treaty with Japan.

Behind the scenes in Singapore, there will be a chance for defence chiefs and other regional leaders to signal more nuanced red lines and create mechanisms to de-escalate crises.

One possibility could be a new communications channel between the heads of US Indo-Pacific Command and China’s Eastern Theatre Command – the two officers who would lead military operations if there was a war over Taiwan, wrote James Crabtree, a columnist in Foreign Policy.

“A military-to-military meeting between the two is unlikely to produce diplomatic breakthroughs. But the fact that it could happen at all is a welcome development — and, given recent years of frosty silence, a somewhat surprising one.”