China’s military conducted a joint training exercise around the disputed Scarborough Shoal in the South China Sea, it announced yesterday, two days after the Philippines accused Beijing of obstructing a resupply mission in another part of the contested waterway.

The People’s Liberation Army Southern Theater Command said in a statement on WeChat that the combined air and naval drill was ⁠a necessary response to actions by “certain countries” that it said had undermined regional ​peace and stability, Reuters reported.

The exercise “aims to test and enhance combat capabilities in safeguarding China’s territorial sovereignty and maritime rights and interests,” the Southern Theater Command said.

The China Coast Guard announced separately that the exercises focused on “maritime rights-protection, law enforcement, and management and control” in the waters around Scarborough Shoal.

A triangular atoll that sits around 200 kilometers to the west of the Philippines’ Luzon Island and 874 kilometers from China’s Hainan Island, Scarborough Shoal has been a persistent flashpoint in the maritime disputes between the Philippines and China. The shoal has been under Chinese control since 2012, when the two nations engaged in a tense 10-week stand-off that concluded with China occupying the feature, despite an agreement for mutual withdrawal from the shoal.

Since then, China Coast Guard (CCG) vessels have surrounded the shoal and made repeated attempts to restrict Filipino fishermen from accessing the rich fishing grounds inside the atoll’s central lagoon.

While the Chinese military did not specify which “certain countries” were the pretext for the joint exercises, it is not hard to guess.

Two days earlier, Manila accused the CCG of obstructing a resupply ​mission to troops stationed at Second Thomas Shoal in the Spratly Islands, prompting a strong rebuke from the Chinese government.

In a statement on Friday, Philippine Coast Guard spokesperson Jay Tarriela said that the mission, which aimed to resupply the troops stationed aboard the BRP Sierra Madre, the grounded warship that functions as Manila’s foothold on the shoal, was “temporarily suspended after a CCG vessel carried out dangerous maneuvers” against the Philippine resupply vessel M/V Lapu-Lapu. The maneuvers “put Filipino personnel at risk” and prevented the mission from being completed, he said.

“There was ​no collision, and no one was injured, but the ​dangerous maneuvers of the China Coast Guard created a serious ⁠risk of collision,” Tarriela added.

For its own part, CCG spokesperson Jiang Lue accused the PCG of engaging in “provocative” acts at Second Thomas Shoal, restating its position that the BRP Sierra Madre was illegally grounded on the shoal in 1999.

“China Coast Guard, in accordance with the law, took measures including on-site monitoring and following, as well as issuing verbal warnings to the Philippine resupply vessel,” it stated. It added that the CCG “will resolutely safeguard China’s territorial sovereignty and maritime rights and interests.”

In a statement, the U.S. embassy in Manila condemned the Chinese action and lauded its Philippine allies’ “professionalism and restraint.”

“The United States strongly condemns the use of dangerous blocking and other irresponsible maneuvers by the China Coast Guard and the People’s Liberation Army Navy (PLAN) that threatened a collision with a Philippine vessel and prevented a lawful and routine resupply mission to Second Thomas Shoal,” it said.

In what has now become a predictable pattern, the Chinese embassy responded by condemning the U.S. for its “insistence on supporting the Philippines’ provocative and unlawful actions at Ren’ai Reef.”

“China urges the U.S. side to stop fanning the flames and refrain from actions that undermine regional peace and stability,” it said.

Friday’s incident comes just over two months after a serious confrontation at Second Thomas Shoal, in which a Philippine Navy marine sustained a head injury after being struck with a baton by CCG personnel, who were taking photos and videos of the grounded warship.

This broke a period of relative calm at Second Thomas Shoal, following a string of increasingly dangerous confrontations between the two sides in 2023 and 2024. These incidents, which stemmed mostly from Chinese attempts to prevent the resupply of the Philippine forces aboard the BRP Sierra Madre, culminated in a July 2024 melee between the CCG and PCG that left eight Philippine naval personnel injured, including one who lost a thumb in the fighting. The two sides subsequently agreed to de-escalate the situation at Second Thomas Shoal, reaching a “provisional understanding” that allowed the Philippines to resupply the grounded warship.

Friday’s interdiction attempt suggests that this “provisional understanding” between Manila and Beijing has now broken down, potentially ushering in a new period of tension at Second Thomas Shoal.