The Chinese military base on Mischief Reef, off the Philippine island of Palawan, loomed in front of our boat, obvious even in the predawn dark.
Radar domes, used for military surveillance, floated like nimbus clouds. Lights pointed to a runway made for fighter jets, backed by warehouses perfect for cruise missile launchers. More than 900 miles from the Chinese mainland, in an area of the South China Sea that an international tribunal has unequivocally determined does not belong to China, cellphones pinged with a message: “Welcome to China.”
The world’s most brazen maritime militarization is gaining muscle in waters through which one-third of global ocean trade passes. Here, on underwater reefs that are known as the Dangerous Ground, the Chinese People’s Liberation Army, or P.L.A., has fortified an archipelago of forward operating bases that have branded these waters as China’s despite having no international legal grounding. China’s coast guard, navy and a fleet of fishing trawlers harnessed into a militia are confronting other vessels, civilian and military alike.
The mounting Chinese military presence in waters that were long dominated by the U.S. fleet is sharpening the possibility of a showdown between superpowers at a moment when relations between them have greatly worsened. And as Beijing challenges a Western-driven security order that stood for nearly eight decades, regional countries are increasingly questioning the strength of the American commitment to the Pacific.
While the United States makes no territorial claims to the South China Sea, it maintains defense pacts with Asian partners, including the Philippines, that could compel American soldiers to these waters. Just as anxiety over nearby Taiwan has focused attention on the deteriorating relations between Washington and Beijing, the South China Sea provides yet another stage for a contest in which neither side wants to betray weakness. Complicating matters, Chinese diplomats and military officers are engaging less at a time when open communication could help defuse tensions.
China’s arming of the South China Sea has also forced Southeast Asian fishermen — from nations like the Philippines that Chinese diplomats have referred to as “small countries” — to abandon the fishing grounds they have depended on for generations. It is putting tremendous pressure on those governments.
“I told the Chinese, ‘Your leadership talks about shared prosperity, but what you are doing cannot make it more plain that you think we are just stupid people who can be fooled and bullied,’” said Clarita Carlos, who until January served as the national security adviser of the Philippines. “The interconnected oceans should be our common heritage, and we should be working with marine scientists from every nation to fight the real enemy: climate change.”
“Instead,” she added, “the Chinese are building military bases on artificial islands and bringing guns to the sea.”
During a four-day sail through a collection of rocks, reefs and islets called the Spratlys that are within the Dangerous Ground, New York Times journalists saw the extent to which China’s projection of power has transformed this contested part of the Pacific Ocean. Not since the United States embarked on its own campaign of far-flung militarization more than a century ago, leading its armed forces toward a position of Pacific primacy, has the security landscape shifted so significantly.
It is hard to imagine how China’s armed presence in the South China Sea will be diminished absent a war. With its bases built and its military vessels deployed, Beijing is forcefully defending its assertions of “indisputable sovereignty.”
That posture was on display in May as The Times’s small, chartered boat passed within two nautical miles of Mischief Reef.
A P.L.A. Navy tugboat lingering in the vicinity had failed to stop us, perhaps because of the early-morning hour. But as we approached the Chinese military base, the tugboat, about 2.5 times the size of our vessel, churned water to reach us, turning on its floodlights and blasting its horn repeatedly. Over the radio, we were told that we had intruded into Chinese territorial waters.
Our boat was Philippine-flagged, and an international tribunal convened by the Permanent Court of Arbitration ruled in 2016 that Mischief Reef was part of the exclusive economic zone and continental shelf of the Philippines. China has ignored that ruling. In a radio exchange, we said we were allowed to sail through these waters.
The P.L.A. tugboat responded with more barrages of its horn, a sonic assault so piercing that we felt it in our bodies. Then, with its floodlights nearly blinding us, the P.L.A. tugboat rushed at our vessel, swiping within 20 meters of our much smaller boat. This was a clear breach of international maritime protocol, maritime experts said.
As dawn broke, we could see both the fortifications on Mischief Reef and an array of Chinese vessels closing in from different directions: half a dozen maritime militia boats and a recently commissioned navy corvette designed to carry anti-ship missiles. The navy tugboat stayed near, too.
On other occasions, Chinese coast guard and militia vessels have rammed, doused with water cannons and sunk civilian boats in the South China Sea. In 2019, for instance, 22 Filipino fishermen were left to float amid the wreckage of their boat for six hours after a Chinese militia vessel struck them.
Danger extends overhead. In May, a Chinese fighter jet sliced past the nose of a U.S. Air Force reconnaissance plane flying through international air space over the South China Sea, echoing an incident last December when a Chinese fighter came within 20 feet of an American plane.
Zhou Bo, a retired P.L.A. colonel who is now a senior fellow at the Center for International Security and Strategy at Tsinghua University in Beijing, said that claimant nations and the United States — which conducts regular air and sea patrols in the South China Sea — should accept Beijing’s contention that this is Chinese turf.
“The U.S. should stop or decrease its operations there,” he said. “But since it is impossible, so the danger will grow. A stronger P.L.A. can only be more resolute in defending China’s sovereignty and national interests.”
Mr. Zhou added that he thought the risk of a conflict between the United States and China was higher in the South China Sea than in the Taiwan Strait, another theater of geopolitical friction.
Frictions in the South China Sea are greatest in places where Southeast Asian countries have defied the Chinese mandate that the waterway, scooped out on Chinese maps with a dashed line, belongs to Beijing. In waters close to Vietnam and Malaysia, Chinese vessels have disrupted attempts to explore and develop oil and natural gas fields. The Chinese coast guard has forcibly prevented its Indonesian counterpart from arresting Chinese fishermen operating well within Indonesian waters.
Chinese forces frequently harass Philippine coast guard boats trying to access a tiny contingent of Philippine marines stationed on Second Thomas Shoal, which, like nearby Mischief Reef, also lies within the Philippines’ exclusive economic zone. (Control over such a zone gives a country the rights to all resources within it, although foreign flagged boats are allowed free passage through most of the waters.)
In February, a Chinese coast guard ship directed a military-grade laser at a Philippine coast guard boat trying to resupply the marines at Second Thomas, temporarily blinding some sailors, according to the Philippine side. The Chinese coast guard has also unleashed high-intensity water cannons at the resupply boats, as recently as last month. In both cases, the Chinese Foreign Ministry said that the Philippine vessels were violating Chinese territorial sovereignty, forcing the Chinese to intervene.
As we left Mischief Reef, with Chinese vessels still shadowing us, we saw just how lopsided the contest is at Second Thomas. In 1997, the Philippines, outmanned and underfunded, beached a World War II era navy ship on the shoal, creating a makeshift base from which its soldiers could defend Philippine waters.
With the marooned navy ship in the distance, we watched as the same Philippine coast guard vessel that had been targeted by the military laser was flanked by a pair of Chinese coast guard ships more than double its length. The radio crackled with verbal jousting.
“Since you have disregarded our warning,” a Chinese coast guardsman said, “we will take further necessary measures in accordance with the law, and any consequences entailed will be borne by you.”
“We will deliver food and other essentials to our people,” the Philippine side answered.
The Philippine boat barely made it through to resupply the marine base. Every week brings such a David and Goliath showdown, and the chance for a dangerous miscalculation.
“The Chinese are flouting the maritime rules of engagement and intentionally violating the good rules of conduct,” said Gregory B. Poling, the director of the Asia Maritime Transparency Initiative at the Center for Strategic and International Studies. “They’re making foreign vessels veer, sometimes at the last moment. One day, a foreign vessel is not going to veer off. And then what?”
Despite its lack of territorial claims in the South China Sea, the American Seventh Fleet regularly cruises these waters to ensure freedom of navigation for all nations, according to the U.S. Navy. (Beijing contends that the presence of American military ships, particularly patrols near Chinese-controlled bases, inflames tensions.) And security pacts bind the American military to several Asian countries. The Philippines, which was once an American colony, is tied to the United States in a mutual defense treaty that Vice President Kamala Harris said last year would extend to “an armed attack on the Philippine armed forces, public vessels or aircraft in the South China Sea.”
This month, U.S. and Philippine warships sailed together in the South China Sea, and the two navies plan a joint patrol later this year.
American support has not always been so full-throated. In 2012, Chinese vessels occupied Scarborough Shoal, off the coast of the Philippines’ most populous island, even after the United States thought it had brokered a deal for both the Philippines and China to withdraw from the reef to cool tensions. Despite the Chinese incursion, American forces did not defend the shoal. Chinese boats have essentially controlled Scarborough ever since.
Around the same time, China began constructing what it said were “typhoon shelters” for fishermen on several South China Sea reefs it controlled. Then Chinese dredgers began piling sand on the atolls. Airstrips and barracks appeared. In 2015, China’s leader, Xi Jinping, stood in the White House Rose Garden and said that “China does not intend to pursue militarization” of the Spratlys, despite satellite evidence that China was doing just that.
“The U.S. response was pretty much limited to statements that they opposed it, but not much more,” said M. Taylor Fravel, the director of the security studies program at the Massachusetts Institute of Technology and an author of books on China’s defense strategy and territorial disputes, noting that the development of the P.L.A.’s South China Sea military bases was done in three phases from 2014-2016. “It’s reasonable to speculate that a much harder response to the first wave would have prevented the next two waves.”
The 2016 tribunal ruling that dismissed China’s “historical claims” over most of the South China Sea came just as the Philippines was ushering in a new president, Rodrigo Duterte, who made close ties with China a signature of his six years in power. Mr. Duterte ignored the tribunal ruling, even though it favored his country. Since President Ferdinand Marcos Jr. took office last year, his administration has spoken out against the Chinese presence in the South China Sea. Mr. Marcos has also granted the United States access to a handful of military bases on Philippine soil and is allowing for the building of others.
After we left Second Thomas Shoal, we sailed toward the Philippine island of Palawan, home to nearly a million people. Green hills rose on the horizon as we neared Sabina Shoal, a rich fishing ground for centuries. In recent years, the Chinese have placed buoys here. The Philippine coast guard has removed them.
Right on Sabina Shoal, where delicate coral once thrived, we saw boats arranged in a defensive formation. Ropes tied some of the vessels together. Chinese flags flew. Men bantered over the radio in a southern Chinese dialect. No fishing nets were in evidence.
China has said that such trawlers are commercial fishing vessels, and a Chinese appetite for seafood has created the world’s largest fishing fleet. But these South China Sea boats, experts say, rarely fish. Instead, they act as a maritime militia, swarming contested waters and unoccupied reefs for days or even months. They have steel hulls and advanced satellites, and some have rammed smaller Southeast Asian fishing boats. If a storm descends, they shelter at Chinese naval bases, like those built on Mischief, Fiery Cross and Subi reefs, satellite imagery shows.
We could see empty Chinese instant noodle packets floating in the water. We heard the Philippine coast guard over the radio, urging the Chinese boats to leave Sabina. There was no response. The Philippine entreaties faded.