The South China Sea disputes are rapidly descending into a quagmire, with potentially explosive ramifications. Shortly after United States President Barack Obama concluded a high-profile summit with Southeast Asian leaders, Chinareportedly deployed an advanced surface-to-air missile system to the Paracel chain of islands, which is also claimed by Vietnam.
In response, Hanoi immediately lodged a formal complaint at the United Nations, accusing its giant neighbour of "serious infringements of Vietnam's sovereignty over the Paracels, threatening peace and stability in the region as well as security, safety and freedom of navigation and flight".
US Secretary of State John Kerry was emphatic, declaring that there "is every evidence, every day that there has been an increase of militarisation [by China] of one kind or another." He vowed to hold a "very serious conversation" with his Chinese counterparts.
One Minute South China Sea
The US also accused China of reneging on its earlier promise, delivered by Chinese President Xi Jinping during his visit to the White House last year, to not militarise the disputes.
Regional powers such as Japan, which heavily relies on the South China Sea for the shipment of its energy imports, have also pitched in. Japanese Defence Minister Gen Nakatani condemned the alleged "unilateral move by China to change the status quo," adding that it "cannot be overlooked".
Chinese officials, however, downplayed the whole affair. Foreign Minister Wang Yi tried to justify the deployment of the advanced military platforms as "limited and necessary self-defence facilities", while the Chinese defence ministry dismissed criticisms over the issue as a Western "hype".
Yet, there is growing fear that Beijing is determined to fully dominate its adjacent waters at the expense of freedom of navigation and overflight in arguably the world's most important waterway.

Failure of engagement

Back in 2013, Obama invited his Chinese counterpart Xi for an intimate, informal summit in Sunnylands resort in California. It was a controversial decision since such "short sleeve" meetings were usually reserved for leaders of the US' dearest allies, such as Japan (as in former Prime Minister Junichiro Koizumi) and the UK (as in Prime Minister David Cameron).
US efforts at constraining China's behaviour has prompted the latter to become even more determined to dominate adjacent waters, undermining freedom of overflight and navigation in a waterway that is pivotal to global commerce and energy transport.

Under his much-touted Pivot to Asia doctrine, the Obama administration was determined to explore a more cooperative relationship with China. In fact, Washington explicitly framed its ties with Beijing as "the most important bilateral relationship in the world," reiterating the necessity for robust engagement with the rising superpower.
Xi, however, had other ideas. He interpreted the whole event as an implicit US recognition of China as its new peer in the Asia-Pacific theatre, calling for a "new type of great power relations". In light of China's insistence that the US should respect its "core interests" (PDF), including its territorial claims in adjacent waters, the statement was interpreted as a thinly-veiled demand for US non-interference in the South China Sea disputes.
In the following months, China pressed ahead with massive reclamation activities across disputed waters, transforming rocks and atolls into artificial islands and building a sprawling network of dual-purpose facilities and airstrips in both the Paracel and the Spratly island chains. It made Obama's engagement policy seem like an unequivocal failure.

Tit-for-tat showdown

Astounded by the sheer scale and speed of China's "revanchist" activities in disputed waters, the Obama administration switched to a more muscular approach. On one hand, it began conducting Freedom of Navigation Operations (FONOPs) in the vicinity of Chinese-occupied land features in the South China Sea. The US began to deploy destroyers and advanced aircraft to challenge China's sovereignty claims.
Admiral Harry B Harris Jr, the commander of the US Pacific Command, effectively warned China by stating that "you will see more of them [FONOPs], and you will see them increasing in complexity and scope in areas of challenge". The latest operation was conducted in the Paracel chain of islands, which most likely prompted China to (once again) deploy the surface-to-air missile platform to the area.
The Obama administration, however, is primarily interested in mobilising a multilateral coalition against China. It has called upon major allies and partners such as Japan, Australia and India to contribute to freedom of navigation patrols in the South China Sea, with Japan's Maritime Self-Defense Force contemplating the prospects of joint-patrols close to Chinese-occupied land features.
To underscore the comprehensive nature of his engagement with Asia, Obama recently also hosted leaders of the Association of Southeast Asian Nations (ASEAN) at Sunnylands, where he managed to garner the support of regional states, including staunch Chinese allies like Cambodia and Laos, to sign a joint statement that implicitly criticised China's activities in disputed waters.
Together with the European Union, the US has also called on China to respect the (likely unfavourable) outcome of the Philippines' arbitration case against China vis-a-vis the maritime disputes. The US and its allies are optimistic that the Arbitral Tribunal at The Hague will rule against China's sweeping claims as well as increasingly aggressive posturing in the area.

The real fear, however, is that China will slowly move towards establishing an Air Defense Identification Zone across the whole South China Sea by deploying surface-to-air missiles and advanced military platforms to airstrips and facilities in the Paracels and the Spratlys.
Ironically, though, US efforts at constraining China's behaviour has prompted the latter to become even more determined to dominate adjacent waters, undermining freedom of overflight and navigation in a waterway that is pivotal to global commerce and energy transport.
Asia, the new centre of global economic gravity, seems to be sleepwalking into an all-out conflict.