The frightening new map of the South China Sea

O31.August A Chinese cutter rammed the Philippine Coast Guard's largest patrol vessel, punching a hole in its side. It was China's latest attempt toTeresa Magbanua Sabina Shoal, where it has been stationed since April. No one was injured. But the incident is part of a new pattern of escalation and confrontation in the South China Sea, particularly around the Spratly Islands. According to a report, Wang Yi, China's top diplomat, warned Jake Sullivan, the American national security adviser, during their meeting near Beijing on August 27 and 28 that China would not accept a Philippine presence in Sabina. The evidence points to a new phase in the battle for the South China Sea, with some Southeast Asian countries pushing back against China. Whether China and America can safely keep the nerve-wracking contest under control is far from clear.

When Xi Jinping came to power in 2012, a major redrawing of the map of the South China Sea began. Over the next three years, China built seven new bases in the Spratly Islands, three of them with major airfields, on rocks and reefs otherwise contested by the Philippines, Vietnam, Malaysia and Taiwan (see map). These bases now house a large, permanent presence of Chinese troops, ships and aircraft, as well as sophisticated intelligence services. Previously, the most elaborate constructions by any country were small airfields on a few islands or outposts on stilts on the coral reefs.

China has attached great rhetorical weight to its vague claim to the part of the South China Sea (that is, almost all of it) that lies within its “nine-dash line.” Sometimes the lines shift on official maps, occasionally adding a tenth line next to Taiwan. But despite the vociferousness of China's claims and the ambiguity of the alleged boundaries, an uncertain status quo has emerged over the past half-decade.

On any given day, one or more Chinese Coast Guard vessels and between a few and a few dozen “maritime militia” vessels (usually large fishing vessels) were stationed at disputed rocks and reefs throughout the sea. Until recently, their remit was mostly limited. Most commercial shipping activity, including container flows on some of the world's busiest sea lanes, was unaffected. China's military and law enforcement agencies were ostensibly preoccupied with a smaller goal: preventing energy exploration and fishing in the area.

And even then, enforcement was poor: a fishing ban imposed by China every summer in the South China Sea (formally to replenish stocks) was not seriously enforced. The American Navy has maintained the practice of sailing through the islands in “freedom operations” to challenge China's claims to the area. In 2015, such operations resumed. However, the number of such trips has declined and China has raised mainly routine objections to them. Meanwhile, the Philippines and sometimes Vietnam have called on the Association of Southeast Asian Nations (ASEAN) to make new statements of concern, but these had little effect. It should not be said too loudly, but for the epicenter of a power struggle between the superpowers, the South China Sea has often been surprisingly quiet.

By comparison, the gusts in this new phase of confrontation threaten to become a storm. The Philippines, Vietnam and Malaysia have begun to push back against China more forcefully. To understand this dynamic, it is important to consider the relative levels of tension across the region. The calmest are the Paracel Islands. China has occupied them completely since it captured them from Vietnam in a battle in 1974. On the largest of the 130 islands, China has an airfield where it has stationed fighter planes.

The situation is more tense in Scarborough Reef, an isolated lagoon. Due to its proximity to Manila, the capital of the Philippines, it is arguably the most strategically important area of ​​the South China Sea. Before 2012, Philippine ships sailed the lagoon's rich fishing grounds, and the Philippine Navy chased away Chinese ships that tried to do the same. But that year, Chinese coast guard ships forced the Philippine ships out. Brazenly, China has controlled the lagoon ever since.

The most explosive are the Spratly Islands. Chinese construction of large bases from 2013 to 2016 took place on reclaimed land. As a result, the islands are now where resistance is fiercest. Since 2022, Vietnam has been dredging and reclaiming land in the areas it occupied: it has now cultivated about half as much land as China (see graphic) and appears to be in the process of building a large airfield. The Chinese government has remained silent on the matter. Malaysia seeks close relations with China and tolerates Chinese ships in the waters it calls its exclusive economic zone. It has also turned a blind eye, or worse, when fleets transfer sanctioned Iranian oil to ships bound for China. Nevertheless, Malaysia relies on energy revenues and has therefore resumed oil and gas exploration off the coast of Borneo near the Spratly Islands despite Chinese objections.

The greatest resistance comes from the Philippines. President Ferdinand “Bongbong” Marcos has instructed his officials to spotlight Chinese activities in the Spratly Islands, including the Philippines’ 200 nautical miles (370.4 km) exclusive economic zone. Of particular note is China’s efforts to prevent supplies from being delivered to a Philippine naval vessel, the Sierra Madrewhich ran aground on the Second Thomas Reef in 1999. Last year, the Philippines began using coast guard vessels to deliver construction materials to Sierra Madre to strengthen its rusting hull. China reacted and successfully blocked the delivery of the Sierra Madre for four months. The small platoon of Filipino marines guarding them gradually ran out of food and water. When the Philippine Navy finally attempted an attack on June 17, Chinese coast guards armed with axes boarded the Filipino dinghies as they reached the shoal and forcibly disarmed the sailors. (The Filipino sailors obeyed orders not to fight back, but one lost a thumb.)

In July, China and the Philippines withdrew from a major confrontation, at least for the moment, in a subdued manner. Chinese diplomats accepted a long-standing invitation from the Philippines to fly to Manila for talks. In the negotiations that followed, they agreed to “preliminary arrangements” that would ensure regular supplies to the Sierra MadreUnder the agreement, China will “inspect” the resupply missions from several hundred meters away to ensure they are not bringing in construction materials. However, Philippine officials say the Sierra Madre has been stabilized with concrete and will not float away (or fall apart) anytime soon. All in all, a temporary victory for the Philippines.

But tensions are also increasing elsewhere, not least at Sabina Reef, where Chinese ships Teresa Magbanua. Philippine officials say they sent their ship into the shoal because they saw signs that China wanted to build something there. But they are playing a risky game. The Philippines did not have a continuous presence in the lagoon before April, so they are changing the status quo, which China abhors. Nor is it clear whether American alliance guarantees to the Philippines apply at Sabina Shoal, as they almost certainly do at Second Thomas Shoal. Under a mutual defense treaty, America pledges to “meet common dangers” should there be an attack on a Philippine state vessel; but while the Sierra Madre is cemented to the Second Thomas Shoal, Teresa Magbanua is in circulation and could therefore be removed.

The real significance of the Sabina incident is that it could trigger another military confrontation at sea. China could make more aggressive attempts to force the Philippines out of the shoal. The wider implications go far beyond a few rocks and ships, as such a confrontation would test America's willingness to come to the Philippines' aid: risking American lives and treasure over an uninhabited shoal would be unpopular in Washington. But if the Philippines pulls out, it is unlikely to get the shoal back. That would bring back memories of the loss of Scarborough Reef in 2012 and raise questions in Manila about the reliability of its larger treaty partner.

The last few months therefore offer two very different visions of how the South China Sea will function in the 2020s and beyond. One is based on the Sierra Madre Episode, points out that the sea is a disputed zone in which all parties are nevertheless able to de-escalate and develop a common understanding of trouble spots. The other vision can be found under Teresa Magbanua: an ever-changing series of mini-confrontations in which China tries to impose its will at sea and Southeast Asian countries fight back. When the defensive actions are carried out by formal allies, America faces a terrible dilemma: does it support them or push them to retreat? China will watch like a hawk to see what happens next. So will other American allies in Asia and elsewhere. ■