HONG KONG (Reuters) - A lack of detailed operational guidelines between the Chinese military and the United States and its allies is heightening fears that a miscalculation or mishap across Asia's crowded seas and skies could get out of control.
When a U.S. guided missile cruiser shadowing China's only aircraft carrier in the South China Sea earlier this month was forced to change course to avoid hitting a smaller Chinese warship, it was seen as the latest sign of how dangerously closely the two navies now operate.
Further north, China's new air defence identification zone over the East China Sea includes the skies above tiny islands administered by Japan that Beijing also claims.
Airborne surveillance and fighter patrols from the United States and its Japanese and South Korean allies are expected to increase to counter any Chinese measures to police the zone, experts said.
"The chance of error is high," said Bonnie Glaser, an expert on Chinese security at the independent Center for Strategic and International Studies in Washington. "If things continue along their present path, you do have to wonder what the consequences will be. There should be an understanding on what constitutes a safe intercept, and there should be reliable communication channels between air forces."
The United States and China probably had the ability to stop an accident between their forces from escalating, Glaser said, but a mishap between China and Japan could be hard to contain given nationalistic and domestic political pressures.
While some routine operational communication has increased - particularly at sea - U.S. and Japanese naval officials and diplomats often voice frustration at what they see as China's slow progress in adopting the sort of detailed operational rules that kept the peace with then-Soviet forces at sea and in the air during the Cold War.
Those arrangements allowed for extensive monitoring and shadowing of rival militaries outside of territorial waters and airspace, with clear understandings that dangerous manoeuvres must be avoided at sea and in the air.
Japan and China agreed in 2011 to hold discussions on setting up a defence hotline for maritime and air emergencies.
But talks stalled after the Japanese government in 2012 bought the islands at the heart of its territorial row with Beijing from a private landowner to fend off a potentially more inflammatory purchase by the Tokyo metropolitan government, at the time headed by a nationalist governor.
While the 1972 U.S.-Soviet agreement has been used widely by Moscow since, China wants different guidelines with Washington, military officials and analysts said.
Beijing has long objected to military surveillance across and above its 200-mile exclusive economic zone - something the United States and other countries insist is international space and therefore open to routine military activity.
An exclusive economic zone is an area that extends beyond a country's territorial sea boundary, giving it rights to oil and fisheries resources but full freedom of passage to foreign ships.
"We're not going to change our position on this, but we do want to firm up some operational norms with China that, put simply, will allow us to operate more safely in each other's space," said one Asian-based U.S. military officer who declined to be identified because he was not authorised to talk to the media.
China sought to put the ball back in Washington's court, saying it wanted more detailed guidelines.
"As far as I understand, not long ago, China proposed wanting to proactively investigate setting military and security rules of behaviour in the air and at sea," Foreign Ministry spokeswoman Hua Chunying said. "We hope the United States can meet us halfway and work hard to increase exchanges, dialogue, cooperation and mutual trust."
Pentagon spokesman Lieutenant-Colonel Jeff Pool said a "sustained and reliable" relationship was vital to managing crises. "Our military-to-military contacts should support deterrence of conflict and lower the risk of miscalculation by encouraging continuous ... discussion of strategic issues, such as maritime security," he said.
Military activity in China's economic zone was the key sticking point, said Ian Storey, a regional security analyst at Singapore's Institute of Southeast Asian Studies.
"China is not going to sign anything that justifies military surveillance by the U.S. and its allies within its exclusive economic zone - it has always said that is illegal," he said. "I think any serious analyst is concerned at the growing risks of some kind of accident in the region spiraling out of control."
Russian and U.S. forces have routinely entered each other's economic zones for decades, knowing they will be monitored and possibly shadowed.
A more limited arrangement between Chinese and U.S. forces called the Military Maritime Consultative Agreement was reached in 1998.
It has led to regular meetings but no hard progress toward improved operational arrangements, said U.S. military officials and analysts, despite a mid-air collision between a Chinese fighter and a U.S. surveillance plane near China's Hainan Island in 2001 and the Chinese blocking of an unarmed U.S. oceanographic ship in the South China Sea in 2009.
In its first comment on the December 5 near-miss involving the USS Cowpens and a Chinese warship off Hainan, China's Defence Ministry said the defence departments on both sides carried out "effective communication".
It was unclear if the vessels were in China's exclusive economic zone at the time.
"China is just uncomfortable with U.S. activities inside its economic zone," said Zhang Baohui, a mainland security academic based at Hong Kong's Lingnan University.
As its reach expands, China's navy has entered economic zones that surround U.S.-ally Japan and the U.S. islands of Guam and Hawaii, but Beijing is probably not ready to negotiate the kind of deal Washington had with Moscow, he said.
"When China's navy is more powerful and feels a sense of equality with the U.S. it might feel more comfortable, but not now," Zhang said.
Indeed, an editorial on Tuesday in Beijing's official China Daily lashed out at U.S. deployments near China's coasts, saying they represented "a growing risk to China's national security".
"Given the behaviour of U.S. warships and military planes near China's coast in recent years, it is clear the U.S. warship was spying and even harassing the Chinese ships," it said.
Operational-level U.S. naval officers have told Reuters of growing contacts with Chinese vessels in the seas around East Asia, as China's navy tests its blue-water capabilities to challenge U.S. dominance of the region's waters.
When Reuters was taken aboard the USS George Washington aircraft carrier as it carried out exercises in the South China Sea last month, officers described being monitored by a Chinese naval frigate 30 km (19 miles) away - well within the carrier's sensitive protective zone, where U.S. escort ships and aircraft are constantly on guard.
"It would be a natural conclusion they would be operating in the vicinity of us," Rear Admiral Mark Montgomery, the carrier strike group commander, said at the time, adding that routine communication with Chinese naval ships was "professional". (Additional reporting by Phil Stewart in WASHINGTON, Ben Blanchard in BEIJING and Linda Sieg in TOKYO; Editing by Dean Yates)