HONG KONG The United States and China are risking a tit-for-tat escalation over the Paracel Islands as Beijing asserts its authority over one of its most tightly-held assets in the South China Sea and Washington challenges a growing military build-up.
Both Chinese and foreign security experts say Beijing won't compromise over the Paracels, and it views its 42-year grip over the entire archipelago as significantly different to the more fragmented situation further south in the contentious Spratly Islands.
China does not acknowledge the Paracels are disputed by neighbouring Vietnam, repeatedly ignoring Hanoi's requests for talks on the Paracels as part of broader territorial discussions and attempting to force them off the regional diplomatic agenda.
"We're in for a difficult time...when it comes to the Paracels, China is not going to budge on what it sees as its absolute sovereign rights," said Zhang Baohui, a mainland security expert at Hong Kong’s Lingnan University.
"We could see China acting more swiftly and decisively to anything it sees as a so-called provocation in the Paracels."
Since the U.S. navy dispatched a destroyer to sail close to the Paracels last month, China has established advanced surface-to-air missiles batteries and re-deployed fighter jets to the islands, prompting U.S.-led protests that Beijing is militarising the South China Sea.
Foreign Ministry spokeswoman Hua Chunying last week reiterated China's insistence that the islands were not in dispute, so Beijing could deploy what it wanted on its territory without reproach.
The Paracels could not be considered part of the landmark declaration between China and Southeast Asian nations in 2002 that calls for peaceful resolution of disputes and self-restraint, she said.
"We have stressed many times that there is no dispute that the Xisha islands are China's sovereign territory," she said, using China's name for the Paracels.
The South China Sea is a vital trade route, linking the large economies of Northeast Asia with South Asia, the Middle East and Europe.
Much of the focus has been on the Spratlys, where China's extensive reclamation and construction on reefs over the past two years is widely seen as presaging Beijing's first military installations deep in the maritime heart of Southeast Asia.
But U.S. moves last month to send the USS Curtis Wilbur patrolling within 12 nautical miles of Triton Island put China's long-established occupation under scrutiny.
U.S. officials privately acknowledge that China's military and civilian presence in the Paracels is more long standing than the Spratlys and that Washington had eyed previous deployments without going public with its concerns.
But given rising regional and congressional concerns, Washington does not want to be seen as taking a soft stance towards any Chinese moves without protest and has promised more "freedom of navigation" patrols.
U.S. Defense Secretary Ash Carter on Tuesday warned China against what he called "aggressive" actions in the region.
"China must not pursue militarization in the South China Sea," Carter said in San Francisco. "Specific actions will have specific consequences," he said, without elaborating.
Carl Thayer, a security scholar at the Australian Defence Force Academy, said he was "simply amazed" by the recent U.S. patrol in the Paracels, which could complicate actions to challenge the newer risks posed by China's work in the Spratlys.
"China's had effectively uncontested control of the Paracels since the 1970s, so they've been militarised for decades," he said. "I think China was really taken by surprise when they sent the Curtis Wilbur."
U.S. and Vietnamese officials protested China's deployment of HQ-9 surface-to-air missiles on Woody Island in the Paracels, fearing a similar move on the Spratlys.
China occupied Woody Island in 1956 and took the rest of the archipelago when it drove off the navy of the then-South Vietnam in 1974.
"The status quo in these two archipelagos is being changed," Vietnam foreign ministry spokesman Le Hai Binh said last week. "The more important and dangerous issue is the militarisation of the South China Sea and these are very serious issues."
While many analysts and regional military attaches believe the recent missile and jet fighter deployments represent Beijing's own protest, some note its determination to better protect its expanding submarine fleet on Hainan Island.
The fleet is expected include several nuclear armed submarines over the next few years, Pentagon surveys show, making Hainan at the core of Beijing's nuclear deterrent.
(Additional reporting by Megha Rajagopalan, Michael Martina and Ben Blanchard in Beijing, Martin Petty in Hanoi and David Brunnstrom and Andrea Shalal in Washington.; Editing by Lincoln Feast)