Watchdog: Beijing upgrades military base on artificial island in South China Sea

China is continuing to reinforce its control and strategic presence across the hotly contested South China Sea, where new satellite imagery indicates expanding military and intelligence capabilities on its artificial island bases. These developments, described in recently analysed satellite photographs, show strengthened electronic warfare, surveillance networks and defensive systems on China’s outposts, signalling the next phase in Beijing’s long-term effort to dominate key maritime territory.

China has worked to consolidate control by maintaining a near-constant presence of naval and coast guard vessels, as highlighted in an article by Newsweek.

These patrols are supported by artificial islands where existing reefs have been transformed into military outposts equipped with aviation facilities, radar systems, runways, and defensive weaponry.

China claims authority over the majority of the region’s islands and maritime zones, basing its position on what it calls “historic rights.” These assertions overlap with territorial claims made by several Southeast Asian nations, creating frequent diplomatic and military tensions.

While China seeks to normalise its military installations as a means of safeguarding sovereignty, its actions have provoked strong responses from the United States. Washington rejects Beijing’s claims and routinely sends warships to challenge what it views as unlawful maritime restrictions. These operations are conducted alongside partners and allies, including Japan and the Philippines, whose vessels also operate in the contested waters. In this environment, the South China Sea has become a focal point for simmering strategic competition between the world’s two largest powers.

The Asia Maritime Transparency Initiative (AMTI) of the Center for Strategic and International Studies (CSIS) published new evidence this week showing further construction on China’s “big-three” reclaimed islands in the Spratly chain: Fiery Cross Reef, Mischief Reef and Subi Reef.

These three outposts, already some of Beijing’s largest fortified locations in the South China Sea, have undergone dramatic engineering projects since 2015. According to CSIS satellite data, Fiery Cross Reef now spans 677 acres of reclaimed land, Mischief Reef has grown to 1,379 acres, and Subi Reef includes 976 acres of artificial surface.

AMTI noted that structures built between 2023 and 2024 likely enhance China’s ability to deploy mobile electronic warfare systems and ISR (intelligence, surveillance, and reconnaissance) equipment. This would increase Beijing’s capacity to monitor regional military activity, jam communications or radar, and coordinate defensive responses across the sea.

The Washington-based organisation also identified additional artillery-ready facilities. On Mischief Reef alone, analysts observed “three sets of three emplacements” constructed in 2023. These positions could support road-mobile rocket launchers or artillery capable of defending the outpost or threatening nearby forces.

China is not the only country that has expanded infrastructure on disputed islands. Vietnam has also been reclaiming land and developing runways or military-grade structures on features it occupies. However, Beijing has consistently dismissed such actions by other claimants. Responding to construction by Vietnam and other Southeast Asian states, the Chinese Foreign Ministry stated that it opposed building efforts on territory Beijing says other governments “illegally occupy.”

An often cited document during diplomatic disputes in the area is the 2016 South China Sea Arbitral Award from the Permanent Court of Arbitration, which ruled in the arbitral tribunal adjudicating the Philippines’ case against China in the South China Sea overwhelmingly in favor of the Philippines, determining that major elements of China’s claim—including its nine-dash line, recent land reclamation activities, and other activities in Philippine waters—were unlawful.

In July, a spokesperson from China’s Foreign Ministry reiterated Beijing’s stance, saying: “China's position on the '2016 Arbitral Award on the South China Sea' is consistent and clear. The 'award' is nothing but a piece of waste paper that is illegal, null and void, and non-binding. China neither accepts nor recognizes the 'award,' and will never accept any claim or action arising from the award. China's territorial sovereignty and maritime rights and interests in the South China Sea will not be affected by the 'award' in any way."

By Nazrin Sadigova