China Begins Construction of New Airbase in Disputed South China Sea

China has begun construction of a runway on Antelope Reef in the Paracel Islands in the disputed South China Sea region.

This was reported by the Asia Maritime Transparency Initiative, an information and analysis project established by the U.S. Center for Strategic and International Studies (CSIS).

Satellite images from August show earthwork. As the researchers note, concrete or other hard surfacing has not yet been laid, and work has begun only on a portion of the probable runway.

However, several signs confirm the construction of an airbase. The width of the section currently being formed matches the width of existing Chinese runways in the South China Sea—about 55 meters.

Such runways are located on the Fayer-Cross, Subi, and Mischief reefs in the Spratly Islands, as well as on Woody Island in the Paracel Islands. Work is continuing along the northwestern edge of the reef—the only straight section on Antelope Reef where a strip about 3 kilometers long can be built, similar to other Chinese outposts.

Other earthworks in the northern section appear to indicate preparations to extend the runway along the entire length of this edge of the reef. Near the future runway, a foundation pit is being dug for at least one structure. Its dimensions—approximately 61 × 61 meters—correspond to the size of large hangars at other Chinese airfields in the South China Sea.

Although this preparatory work marked the first sign of construction of large infrastructure projects on Antelope Reef, the reef itself has changed significantly since work began. Land reclamation and dredging appear to have been completed: dredgers are not visible in recent images. The area of the reclaimed island now stands at about 590 hectares, significantly exceeding the historical area of the natural shoal—about 1 hectare.

In recent months, several new buildings have been erected on the artificial island. The development of green spaces and paved parking lots is transforming this remote outpost into an administrative center typical of other Chinese islands.

Other notable structures include two concrete plants that appeared in late spring along the northwestern and southern shores of the lagoon. These are likely temporary facilities that will play a key role in supplying materials for the construction of other infrastructure. They may eventually be relocated or replaced by permanent structures.

Disputed territories in the South China Sea

The South China Sea, covering an area of more than 3.5 million square kilometers, plays a critical role in the global economy. About one-third of all global maritime trade passes through its waters. This vast body of water is the subject of fierce and mutually exclusive territorial claims by Brunei, Indonesia, Malaysia, the Philippines, the People’s Republic of China (PRC), Taiwan (the Republic of China), and Vietnam.

China views this body of water through the lens of historical rights, citing maps from 1775, 1810, and 1817 and claiming that these territories have long belonged to China. In 1953, the communist government of the PRC established the infamous nine-dash line. This line encompasses nearly 90% of the sea, grossly violating the exclusive economic zones (EEZs) of all neighboring states.

The Paracel Islands are a disputed territory between the PRC, Taiwan, and Vietnam. China has effectively controlled them since a one-day battle with Vietnam over the islands in 1974. There is currently no internationally recognized decision regarding sovereignty over these islands. At the same time, the 2016 ruling by the tribunal in The Hague effectively undermined the legal basis for China’s historical claims to most of the waters within the nine-dash line.

In response to China’s increased activity, Vietnam, for its part, has also stepped up the creation of artificial land features in the Spratly Islands region, gradually closing the gap with China.