China warns Philippines over South China Sea tensions amid US-Japan drills — what to know

China has issued a sharp warning to the Philippines, cautioning against what it described as “provocative actions” in the South China Sea, as its forces step up patrols in contested waters.

The statement came from the Southern Theater Command of the Chinese military, which directly addressed Manila while criticizing its growing defense cooperation with the United States and Japan. The command accused the Philippines of escalating tensions by inviting “external forces” into the region, a reference to joint maritime exercises that concluded this weekend.

“We seriously warn the Philippine side to cease stirring up incidents and to avoid relying on foreign backing for efforts that will ultimately fail,” the spokesperson said, insisting that any bid to challenge Beijing’s position in the waterway was “doomed to go nowhere.”

Joint Exercises Test Regional Nerves

The warning followed a three-day naval exercise conducted in the Philippine Exclusive Economic Zone involving the US, Japan, and the Philippines. According to the US Indo-Pacific Command, the drills focused on enhancing interoperability and reaffirming a shared commitment to a “free and open Indo-Pacific.”

Washington emphasized its stance on international law, with the command noting that the US and its allies “uphold freedom of navigation and overflight, along with respect for maritime rights as guaranteed under international law.”

Flashpoint: Scarborough Shoal

The flare-up comes just days after Beijing announced plans to establish a 3,500-hectare nature reserve on Scarborough Shoal, a tiny but hotly contested outcrop also claimed by Manila. The move immediately drew a protest from the Philippine government, which views the area as part of its sovereign territory.

US Secretary of State Marco Rubio added his voice to the backlash on Friday, condemning Beijing’s move as “yet another coercive attempt to advance its maritime claims at the expense of regional stability.”

Strategic Stakes in the Waterway

The South China Sea remains one of the world’s most strategically vital regions, with more than $3 trillion in trade passing through its waters every year. China claims nearly all of it under its “nine-dash line” doctrine, a claim rejected by an international tribunal in 2016 but enforced by Beijing through island-building, military installations, and regular patrols.

The Philippines, along with other Southeast Asian nations, continues to challenge China’s sweeping claims, leaning increasingly on support from allies like the US and Japan. With each new exercise and counter-move, the region edges closer to confrontation — a prospect that keeps the South China Sea among the most volatile flashpoints in global geopolitics.