Tensions between China and the Philippines escalated rapidly following a violent clash last week between their sailors in the South China Sea (SCS). Videos published by the Philippine military showed Chinese Coast Guard personnel ramming and boarding Philippine naval boats and confiscating their weapons.

Philippine officials claimed the Chinese borders were armed with swords, spears and knives. They said several Filipinos were injured in the incident, including one sailor who lost his thumb.

While Manila described the Chinese as behaving like "pirates," Beijing justified its actions by claiming the Chinese side simply took "necessary measures" such as interceptions and boarding inspections to safeguard the country's sovereignty in a "professional and restrained" manner.

The clash was the latest in a series of escalating confrontations between Chinese and Philippine vessels in recent monthsoff the disputed Second Thomas Shoal, where a tiny Philippine garrison is stationed on an old warship BRP Sierra Madre that was deliberately beached.

The Philippine boats were on a resupply mission last week when they were attacked by the Chinese Coast Guard.

Latest clash 'concerning'

Analysts have found the latest skirmish especially "concerning" as any accident involving severe injuries has an increased chance of escalating into a situation where both sides find it difficult to back down.

Bonnie Glaser, managing director of the Indo-Pacific Program at the German Marshall Fund of the United States, told DW that "it isn't difficult to envision a scenario in which someone is accidentally killed" — given the current tensions in the region. 

"The risk of an accident that escalates to conflict is high," she said.

China and the Philippines have been locked in a years-long dispute in the SCS.

Beijing claims almost the entire waterway with its so-called nine-dash line, which overlaps the exclusive economic zones of rival claimants Brunei, Malaysia, Philippines, Taiwan and Vietnam.

The Philippines uses the West Philippine Sea name for the portion of the SCS that it claims.

In 2016, an international tribunal in The Hague ruled in favor of the Philippines and invalidated China's claim in the strategic waters.

But Beijing refused to accept the ruling.

China's 'risky strategy' of provoking the US ally

China has also become more assertive in its maritime territorial claims, leading to multiple clashes where Philippine ships have been damaged and Filipino sailors injured by water cannons over the past year.

In response, Philippine President Ferdinand Marcos Jr. has sought closer ties with the United States.Manila signed a mutual defense treaty (MDT) with the US in 1951. The pact commits both sides to help defend each other if either were attacked by a third party.

"China is increasingly interested in pushing the Philippines-US alliance to its limit," Don McLain Gill, a Manila-based geopolitical analyst and lecturer at De La Salle University, told DW.

Following the recent clash, US Secretary of State Antony Blinken spoke to his Philippine counterpart and once again underscored Washington's "ironclad commitments" to its ally under the treaty.

But Gill said more US action is needed in the region. 

"If left unchecked, it is likely that Beijing will push the Philippines further," he noted, adding that China's purpose is to show that the alliance formed by Manila and Washington is "unable to act" despite their political statements.

Glaser said Beijing is deliberately trying to "bully" Manila and "compel it [to] return to talks with China."

But this strategy is "risky," the expert stressed, as the Philippine leader has recently lowered the bar for invoking the defense treaty with the US.

Earlier this month, at a global defense forum in Singapore, Marcos was asked how his country would react to a hypothetical situation where Chinese actions killed a Filipino soldier and if that would trigger the US-Philippines treaty.

The Philippine president responded by saying that if by a willful act, a Filipino citizen — not only servicemen — is killed, it will be "very close to an act of war" and "the Philippines will respond accordingly."

As for the latest row with the Chinese, however, the Philippine officials later said Manila did not consider invoking the treaty despite a Filipino sailor having his finger cut off.

Possibility of de-escalation?

Two days before the latest clash, the Philippines had filed a submission to a United Nations body asking for the recognition of the outer limits of its continental seabed in parts of the disputed waterway.

Beijing denounced Manila's claim as a serious infringement of Chinese sovereignty and has formally urged the intergovernmental organization not to review the appeal.

Chong Ja Ian, an associate professor of political science at the National University of Singapore, said Manila's latest resort to the UN is part of the reason why Beijing believes it needs to behave "more forcefully."

At this stage, he told DW, any possibility of de-escalation is more "in the hands of Beijing" as, in his view, China is the most capable disputant and the one most willing to use force. 

Despite the aggressive moves, Chong pointed out, China did not sink the Philippine vessels or detain them and their crew — which suggests that Chinese personnel are still aware of the need to "prevent escalation from getting out of control."

From Manila's perspective, Gill believes the country needs to "learn" from the incident and pursue a "more effective physical deterrence strategy," such as equipping the Filipino crew with non-lethal weapons and training.

"It is one of the ways that will increase the cost for Beijing," Gill said, adding that it could result in Chinese maritime personnel easing their actions after realizing that nothing much could be gained from them.

Edited by: Srinivas Mazumdaru