The U.S. is pledging to sail more warships past the shores of artificial islands in the South China Sea as the world's most powerful military seeks to strip away the expansionist claims of China and other nations in waters crucial to the global movement of goods.
Early Tuesday morning, the guided-missile destroyer USS Lassen deliberately came within 12 nautical miles of Subi Reef, one of the places in the Spratly Islands that China has transformed into a sizable air and sea outpost from a reef that once vanished at high tide.
In so doing, the ship breached the exclusion zone that would apply to territorial waters and underscored the U.S. position that China cannot claim that exclusion around its manufactured lands. The move escalates the conflict over who controls a sea the size of India that constitutes the maritime heart of East Asia. It provoked an angry response from China, which dispatched a missile destroyer and a patrol boat to shadow and attempt to warn off the Lassen.
In Beijing, China summoned U.S. Ambassador Max Baucus over the patrol, which vice-foreign minister Zhang Yesui called "extremely irresponsible," while other officials warned of a Chinese retaliation.
If Washington "keeps stirring things up and hyping up tension, then the Chinese side may have to arrive at one conclusion: that it is necessary for us to strengthen and speed up relevant construction activities," said Foreign Ministry spokesman Lu Kang. "We hope the U.S. side will not take actions that will backfire."
He said China "has indisputable sovereignty" over the Spratly Islands "and the adjacent waters."
Each year, $5.3-trillion (U.S.) worth of trade crosses the South China Sea. China claims most of it as its own and has sought to strengthen its hold in the past 18 months by dredging out more than eight square kilometres of dry land atop reefs that were once submerged beneath high waters.
The U.S. has accused China of building a "great wall of sand" in the region that threatens the ability of military ships and, perhaps one day, commercial vessels to transit those important waters. White House spokesman Josh Earnest on Monday said Washington acted because ensuring "that freedom of navigation of those vessels is protected is critically important to the global economy."
U.S. officials said more sailings would be conducted in the future, including around sea installations built by Vietnam and the Philippines.
China has been the most eager developer in the area, building island runways, ports and other facilities that could be used by its military. But it has not clarified the basis for its activities or underlying claims, creating a legal murkiness that has sparked conflict with numerous neighbours who can point to the laws of the sea and the way China is violating them. Even the term "indisputable sovereignty" is not a legal one.
"The only way they can make this lawful is to completely renounce what they're doing," said James Kraska, an authority on the issue who is a researcher at the U.S. Naval War College. "It's a political issue, because legally it's an open and shut case. It's untenable."
He added: "The problem is it does not appear that China accepts universal values. It accepts one set of rules for itself and another set of rules for other countries."
And the politics are potent, with Washington and Beijing jousting for influence over a crucial body of water. Each country has reason to appear strong: The U.S. to reassure friendly nations – Japan, the Philippines and Taiwan among them – that it remains a credible guarantor of regional security; China to prove to its people that it is a strong nation capable of defending its sovereignty.
Maritime disputes of this nature do not lend themselves to easy resolution, with North and South Korea butting heads over their sea boundary since 1953, and Canada similarly unable to agree with the U.S. on the status of the Northwest Passage.
The U.S. use of a warship is a sign of frustration at China's continued island construction, said Yanmei Xie, China analyst with the International Crisis Group. "The U.S. is showing it has the capability and has the commitment to respond to what they perceive as Chinese transgressions in the South China Sea," she said.
Senator John McCain has warned that without a direct challenge, the U.S. risks giving China "de facto recognition" over the artificial islands.
In sovereignty disagreements, "if you don't do anything more than utter your disagreement, essentially over extended periods of time it becomes a fait accompli," said Robert Karniol, who spent more than two decades covering Asia security issues for Jane's Defence Weekly before retiring recently.
Nationalist Chinese newspapers have warned that if Washington seeks to have Beijing "halt its activities, then a U.S.-China war is inevitable in the South China Sea."
But Mr. Karniol called that so much "huffing and puffing." He added: "It's political one-upmanship on both sides, and it's not something to fight a war over."
(Because of the legal principles at play, the South China Sea issue has been tricky for countries such as Canada, which does not want to support the U.S. in Asia and risk hurting its Northwest Passage claim.)
The sailing of the Lassen nonetheless comes amid growing worry about danger in Sino-American relations, as a rising power challenges a settled one. Drawing on 16 such examples from history, researchers at Harvard University found 12 resulted in conflict. "Could the U.S. and China find themselves at war in the decade ahead?" asked Graham Allison, director of the school's Belfer Center for Science and International Affairs. "On the historical record, it's more likely than not."
Regional experts, however, suggested the greatest threat for now appears to be an accident, particularly if China aggressively shadows American vessels. "It will be a source of tension between them for the foreseeable future. But neither country wants to get into a conflict over this," said Ian Storey, a senior fellow at the Institute of Southeast Asian Studies in Singapore.
But bigger issues may lie on the horizon, he warned, including the likelihood a January election in Taiwan will install a new government that is less friendly toward Beijing. "Given the hardline stance the Xi Jinping government has taken on sovereignty issues, I think this could be a real problem in the future," said Mr. Storey.
"Taiwan will come front and centre, because for China that's a much more important issue than these little rocks and atolls."