At high tide, the tiny coral shelf in the Paracel chain known as Antelope Reef was only just underwater but now it is a six-kilometre island with a deep-water port, a quay large enough to accommodate a warship and a base for a runway, which analysts say will exceed 9,000 feet in length. The dredgers and barges that worked the site around the clock for some 10 months have now departed, according to commercial satellite images the Reuters news agency reviewed this week and separately the Asia Maritime Transparency Initiative. Phase one of the project is "over," officials in the region say. What is left is a shoreline that is over three kilometres in length and straight and long enough, according to several defence analysts, to support a military-grade airstrip when paved.

The scale is worth repeating as it turns 10 years of assumptions on their head. In 2015, through Xi himself, China declared to the world that the reclamation work in the Spratlys had come to an end. Nearly 10 years, the near eyes on the waterway have taken it on faith that Beijing is consolidating, not expanding at Fiery Cross, Subi and Mischief reefs. That's the problem that Antelope sets out to solve. AMTI's researchers estimate it will surpass Mischief Reef, which is roughly 1,504 acres, as the single largest man-made island in the entirety of the South China Sea, by the time the project is finished.It is the first large-scale island-building project in China since 2017, and according to AMTI's researchers, it will outcompete Mischief Reef, which is the largest artificial structure in the Spratlys, at approximately 1,504 acres when it is completed. It would also be the size of Paracels' administrative and military centre of Woody Island which is approximately 890 acres in size housing fighter jets, surface to air missiles and a garrison town.

The timing is significant in that it started quietly. Tracking data and independent reporting from Asia Times showed that the dredging vessels were assembled in the estuary of the Zhujiang River in October last year, and then sailed to the reef with their transponders turned off. The level of operational secrecy not seen in previous reclamation efforts by China, which were almost done in the open indicates that Beijing was not unaware of the diplomatic repercussions and wanted to create a lead in the eyes of satellite operators. This didn't last very long. By January reports of strange activity around the reef had come to light, and within a few weeks, AMTI and Janes were publishing images of roll-on, roll-off berths, dredging gear and the beginnings of a stable landmass on top of what had been little more than a sandbar.

In March, Vietnam formally protested, claiming the entire Paracels and saying that the reef was called Da Hai Sam, or the “Da Ha Island.” Vietnam's foreign ministry spokeswoman stated that any illegal construction on the reef is “completely illegal and invalid.” Hanoi has maintained that objection in official forums, but has yet to resort to the type of confrontational actions the Philippines has faced in the past off the coast of Second Thomas Shoal, some 400 miles to the south, where Chinese coast guard vessels have deployed water cannon and military-grade lasers against Filipino resupply vessels. The regionals read it as intentional: Beijing is seen as adopting a country-by-country approach to pressure and is squeezing Hanoi, but not Manila, which also reflects the alignment of the two countries with Washington. Since 2023, the Philippines has allowed American access to nine bases under its territory and has welcomed Japanese and Australian troops as well as over 500 planned exercises with the American military in this year's Balikatan drills. Vietnam has gone more slowly, despite quietly acquiring more territory in the Spratlys and American naval visits of a more prominent nature to Da Nang.

This maneuvering is not just economic, it is huge. Somewhere between a fifth and a third of all global shipping goes through the South China Sea, which is estimated to be home to between 3.5 and 5.3 trillion dollars in trade each year, depending on the method used. Over 40% of China's maritime traffic, more than 40% of Japan's, and most of South Korea's energy imports, as well as significant volume of goods destined for and from India via the Malacca Strait choke point, pass through these waters. There are estimated to be more than 200 billion barrels of oil equivalent resource under the sea, combined with significant untapped natural gas and rare-earth deposits that are the reason why Vietnam, the Philippines, Malaysia, Brunei and Taiwan have all rejected China's over-sized navy and coast guard fleet in advancing their claims. In a 2016 case filed by Manila, a UN Convention on the Law of the Sea tribunal determined that Beijing's nine-dash claim is without legal foundation. China did not accept the verdict then and has kept on constructing ever since.

The countries that are not directly involved in the conflict are more concerned with the operational consequences of a runway at Antelope rather than about its territorial sovereignty. The base would be deployed in the northern approaches to the sea, about 160 nautical miles south of Hainan, and near shipping lanes that are some of the busiest in the world as well as closer to potential points of conflict with Taiwan than any existing Chinese facility is in the Paracels. The fact that Beijing may choose to either call the completed island a weather station, as it did decades ago for Woody Island, or to outright admit it as military infrastructure means the same thing will happen with regard to how it affects freedom-of-navigation calculations for the U.S., Japan, Australia and India's orientation to the east.