China's deployment of missiles on a disputed island in the South China Sea suggests that Beijing is prepared to escalate tensions in order to defend its territorial claims. It is also a deliberate effort to progressively extend China's strategic footprint in the region, experts say.
With a ruling expected this year on an arbitration case that the Philippines has brought before an international tribunal, and recent freedom of navigation (FON) missions by the US, the deployment may not be just a military move but one with signalling elements as well, they add.
Reports surfaced on Wednesday - just hours after US President Barack Obama wrapped up a summit with Asean leaders in California - that Beijing had deployed surface-to-air missile batteries to Woody Island, part of the Paracel chain also claimed by Vietnam and Taiwan.
"In a political context, China's latest move coincides with the summit for Asean leaders being hosted by Mr Obama," said Dr Euan Graham of the Lowy Institute.
"The appearance of the missiles could be interpreted as a warning to South-east Asian leaders not to tack too close to the US in the South China Sea," he wrote in a commentary for The Guardian.
But the deployment also marks a step up the ladder to China's progressive "militarisation" of the resource-rich waters, and is also a calibrated one, Dr Graham added.
"If China's long-term strategy seeks military predominance in the sea, one near-term motivation for the missile deployment could be to deter the US from mounting an overflight operation close to the Paracels," he said.
The US has twice sent warships, most recently last month at the outer Paracels' edge, within what China considers its territorial waters, to assert its right of FON. China has competing claims in the sea with Brunei, Vietnam, the Philippines, Malaysia and Taiwan.
Chinese state media went on the defensive yesterday, arguing that the Paracels - unlike the Spratlys, another contested island chain - are firmly in China's control. Beijing seized them from South Vietnam in 1974.
"Defensive weapons were deployed on (Woody) island in the past. Even if the presence of the (missile) system is true as the West has claimed, it is a matter of China's sovereignty and it is fully legitimate for China to do so," said a Global Times commentary.
Added Renmin University's international relations professor Shi Yinhong: "To China, placing military facilities on the Paracels is like placing them in Shanghai as Beijing believes there is no question to its sovereignty there."
Dr Mark Valencia, an adjunct research fellow at the China National Institute for South China Sea Studies, said that when this position of Beijing's is considered, the deployment should not be viewed as a provocative act.
"But because the US has challenged its baselines and prior notification regime there, Beijing probably sees a need to bolster its defence," he added.
Experts point out that Chinese President Xi Jinping had referred specifically to the Spratlys, and not the Paracels, when he said that China "does not intend to pursue militarisation" in the South China Sea last September.
"(The deployment) is also a way of testing international reaction as a potential precursor to the militarisation of its artificial structures in the Spratlys, or even the declaration of an air defence identification zone in the South China Sea," Dr Graham wrote.
Still, the deployment increases the possibility of an escalating tit-for-tat game of strategic signalling, especially the risk of miscalculation between Beijing and Washington.
Experts warn that, with the sea already home to runways capable of launching fighter jets to patrol the sea, and now missiles that could target wayward planes, the stakes have grown higher.
Prof Shi said a gradual arms race in the region has already begun.
"We are seeing more naval forces gather and claimant states are also buying weapons. But it's most important that the red line of the US and China engaging in military conflict is not crossed."