China and the United States have clashed again over the disputed waters of the South China Sea, raising fears that escalating tensions could result in a dangerous miscalculation that might lead to accidental military conflict.
It did not help that US Secretary of State John Kerry failed to refute reports that the Pentagon is mulling over having ships and planes expand patrols to disputed areas, including within 12 nautical miles of islands, in a direct challenge to China's territorial claims, at a press conference with Foreign Minister Wang Yi on Saturday.
A Global Times editorial last Thursday warned the US threat to expand its patrols was a provocation that could turn the sea into "a powder keg".
China has overlapping territorial claims in the waters with the Philippines, Vietnam, Malaysia, Brunei and Taiwan. Beijing's activities, including reclamation works on disputed isles, led ASEAN to express concern over the impact on freedom of navigation and overflight at a summit last month.
With the latest US response raising the stakes, what are the possible scenarios in the area?
Accidental armed conflict
Some experts say if the US does deploy its military to within 12 nautical miles of reefs claimed by Beijing, it would result in an escalation of tensions that might set the stage for miscalculations and mishaps.
A military stand-off and any exchange of fire would be the worst-case scenario, they say.
Defence News' Asia bureau chief Wendell Minnick said while it is very unlikely, the possibility of "a Chinese commander firing an anti-ship missile and having things escalate from there" cannot be ruled out. "The nationalistic fervour is so great right now that you're not sure how far that might push a commander."
The reaction of the Chinese navy also remains a huge source of uncertainty as it has not been observed in combat before, Mr Minnick noted, adding that the Sino-US crisis management mechanism meant to avoid unwanted clashes can also be improved.
But Singapore-based analyst Li Mingjiang said close-range manoeuvres and a military stand- off would be the worst case scenario, with any exchange of fire "almost impossible".
China is likely to use "swarming tactics" rather than a direct military confrontation, Mr Minnick said. This means sending Chinese fishing boats and coast guard vessels to harass the US ships while the Chinese navy watches at a distance, Beijing's usual tactic.
He said: "But the US military can't do this forever. It is likely to demonstrate its physical presence, then slack off before bringing it back during a crisis."
Professor Li thinks the most likely scenario would be the US incursions occurring but for them to be mostly "symbolic".
"No one is looking for a fight so it might just be one or two vessels crossing the borders of the 12-mile zone and not staying long," he said. "The Chinese are unlikely to react harshly and will just monitor and follow them."
White House votes 'no'
US President Barack Obama might choose not to approve the Pentagon proposal.
In a meeting with General Fan Changlong, vice-chairman of the Central Military Commission, Mr Kerry had said reports on the issue "do not reflect any political decision by the US government", according to the Xinhua news agency.
Analyst Huang Jing of the Lee Kuan Yew School of Public Policy said the plan could have been leaked to the media as part of the US' attempt to send a positioning message to China, while not excessively escalating tensions since Washington still needs Beijing's co-operation on many other issues.
"It wants to warn China that if it does not behave, this is what the US plans to do."
This article was first published on May 19, 2015.
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