China’s Defense Minister Dong Jun warned over the weekend that Beijing’s restraint in the South China Sea (SC) has limits, in a thinly veiled threat to the Philippines and United States over their presence in the disputed waters.

Speaking at the Shangri-La Dialogue conference in Singapore on Sunday, Dong referenced a “certain country,” encouraged by external powers, which had allegedly engaged in “mediated provocations.”

“China has maintained sufficient restraint in the face of rights infringements and provocation, but there are limits to this,” Dong said.

The Chinese official’s comments followed President Ferdinand Marcos Jr’s denunciation of “illegal, coercive, and aggressive actions” in the South China Sea by China in the same defense forum in Singapore last Friday.

Marcos warned that the death of any Filipino citizen at the hands of another country in the South China Sea would be “very close” to an act of war.

“What would happen if there was an incident that ended up killing a Filipino serviceman, be it a Coast Guard or in the military and part of the Navy. Well, that would be — that would certainly increase the level of response and if by a willful act on a Filipino, not only a serviceman but even a Filipino citizen. If a Filipino citizen is killed by a willful act, that is I think a very, very close to what we define as an act of war and, therefore, we will respond accordingly,” he said.

MDT invocation

Marcos made the response when asked what actions would prompt the Philippine government to invoke the decades-old Mutual Defense Treaty (MDT) with the United States. The treaty holds that both countries would come to the defense of each other in case of an attack by a third party.

Beijing has frequently accused Washington of supporting Taipei and Manila in resisting its assertive actions in the Taiwan Strait and the South China Sea.

Last month, the Pentagon deployed an intermediate-range missile system in the Philippines during the annual Balikatan military drills, which Beijing condemned as introducing “huge risks of war into the region.”

China asserts control over nearly all of the South China Sea, a vital route for over $3 trillion in annual ship-borne trade. This claim includes areas also claimed by the Philippines, Vietnam, Indonesia, Malaysia, and Brunei. In 2016, the Permanent Court of Arbitration ruled that China’s claims had no legal basis.

Taiwan issue

In response to Chinese actions in the region, Marcos has pursued closer relations with the United States.

Also on Sunday, Chinese state media reported that personnel on a Philippine ship aimed guns at China’s Coast Guard in the SCS. Philippine officials have yet to respond to the claim at press time.

CCTV maintained at least two individuals on the Philippine vessel near the shoal were seen carrying guns on deck, pointing them toward the CCG ship, according to China’s CCTV news channel.

An accompanying 29-second video seemed to show a masked man briefly holding up a blurred black object resembling a rifle. CCTV claimed that the purported incident took place during a Philippine mission to deliver supplies to troops.

Given its position in the South China Sea and proximity to self-ruled Taiwan, which China claims as its own, Philippine support would be crucial for the United States in the event of any conflict.

Dong also reiterated that China is ready to “forcefully” stop Taiwan’s independence moves but called for greater exchanges with the United States.

“We have always been open to exchanges and cooperation, but this requires both sides to meet each other halfway,” Dong told the meeting where he met with US Defense Secretary Lloyd Austin on Friday.

“We believe that we need more exchanges precisely because there are differences between our two militaries.”

Dong and Austin met for over an hour at the luxury hotel hosting the forum, which is attended by defense officials from around the world and in recent years has been seen as a barometer of US-China relations.

After the meeting, Austin said that telephone conversations between US and Chinese military commanders would resume “in the coming months”, while Beijing hailed the “stabilising” security relations between the countries.

This year’s Shangri-La Dialogue comes a week after China held military drills around self-ruled Taiwan and warned of war over the US-backed island following the inauguration of President Lai Ching-te, who Beijing has described as a “dangerous separatist”.

“The Chinese People’s Liberation Army has always been an indestructible and powerful force in defence of the unification of the motherland, and it will act resolutely and forcefully at all times to curb the independence of Taiwan and to ensure that it never succeeds in its attempts,” Dong told the forum on Sunday.

“Whoever dares to split Taiwan from China will be crushed to pieces and suffer his own destruction.”

On the South China Sea, which China claims almost entirely and where it has been involved in confrontations with Philippine vessels, Dong warned of “limits” to Beijing’s restraint.

“China has maintained sufficient restraint in the face of rights infringements and provocation, but there are limits to this,” Dong said.

Flashpoint disputes

President Joe Biden’s administration and China have been stepping up communication to ease friction between the nuclear-armed rivals, with Secretary of State Antony Blinken visiting Beijing and Shanghai last month.

A key focus has been the resumption of military-to-military dialogue, which is seen as critical to preventing flashpoint disputes from spinning out of control.

China scrapped military communications with the United States in 2022 in response to then-US House Speaker Nancy Pelosi’s visit to Taiwan.

Tensions between Washington and Beijing were further stoked by issues including an alleged Chinese spy balloon that was shot down over US airspace, a meeting between Taiwan’s then-president Tsai Ing-wen and Pelosi’s successor Kevin McCarthy and American military aid for Taipei.

China is also furious over the United States’ deepening defence ties in the Asia-Pacific, particularly with the Philippines, and its regular deployment of warships and fighter jets in the Taiwan Strait and South China Sea.

Beijing views this as part of a decades-long US effort to contain it.

The two sides agreed after a summit between Chinese leader Xi Jinping and Biden last November to restart high-level military talks, including over military operations near Taiwan, Japan and in the South China Sea.