Torpedo report poses dilemma for Beijing
It may have been the worst kept secret in the region, but the official conclusion that it was a North Korean torpedo that sunk a South Korean warship in March brings fresh and potentially damaging complications for China.
In Seoul, South Korean officials insist they are now pushing Beijing for far greater involvement in pressuring Pyongyang, China's fraternal but prickly ally.
In coming days that is certain to mean pressure for China's acceptance of tough new sanctions via the UN Security Council and/or a swift apology from North Korea, a recalcitrant state hardly known for its mea culpas in the past.
And while China, together with the US, is likely to be cautioning South Korea against any action that provokes escalation from their North Korean enemies, Seoul has deliberately not taken a possible military response off the table.
'I'm sure China would like to swiftly smooth things over and return to the status quo, something that is of course in their favour,' one official said from Seoul.
'But it is not that simple. They have to understand that this is a massive issue for South Korea, even bigger than a nuclear test. Forty-six naval sailors have been killed. This is an act of war that demands a robust response,' the Seoul official said.
'Our public are shocked and enraged and no one can blame them ... this issue cannot simply be left to quietly go away, because it won't.'
Beijing officials have already suggested to their Seoul counterparts that not only does China have limited leverage over its hermit neighbour despite being its sole ally, but it is also constrained by its traditional policy of non-interference in countries' affairs. Even to push too hard for an apology - an act which could ease tensions until a longer-term response is found - would risk breaching those principles.
'At the moment, any such explanation is not really acceptable. We are still talking and still pushing for something harder. We urge China, and the rest of the region for that matter, not to underestimate the pain the act has caused,' an official said.
Despite ongoing difficulties over North Korea, South Korea and China have significantly improved ties in recent years, reflecting strong trade, tourism and cultural exchanges.
Publicly at least, Chinese officials are keeping their cards close to their chest as they digest the sinking report from the team of investigators from South Korea, the US, Sweden and Australia.
The investigators yesterday cited overwhelming evidence that a North Korean submarine fired a torpedo at the corvette Cheonan on March 26, tearing it apart.
'There is no other plausible explanation,' they said in their report, detailing similarities between salvaged torpedo fragments and those routinely used by North Korean submarines.
Foreign Ministry spokesman Ma Zhaoxu urged parties involved to remain 'restrained and calm' over the handling of the sinking of the warship. 'China has taken note of the investigation result by South Korea. We call on all relevant parties to exercise restraint to avoid further tensions.'
Ma said China was accessing Seoul's investigation report but would not say how long its own assessment would take.
Ma evaded repeated questions on whether China would condemn North Korea if it proved to be responsible for the sinking of the Cheonan.
North Korea dismissed the sinking report as sheer fabrication and threatened 'all-out war for justice' if there was any attempt to punish it.
The two sides have remained technically at war since the Korean conflict ended with an armistice in 1953 - the basis of the fragile peace that has lasted since then. The border between the two states is the most heavily fortified anywhere - a cold war relic that includes tens of thousands of North Korean artillery pieces aimed at Seoul.
While South Korea is one of the world's most technologically advanced societies, North Korea is the world's sole remaining hermit state - a closed nation that relies on food aid to feed itself and is ruled by a tiny military and Communist Party elite surrounding the dynasty of Kim Jong-il.
Instinctively, China would prefer to continue to prop up Kim rather than back any action that would risk the North imploding in chaos that would spill into its territory and, perhaps, drive South Korea and its ally the United States to its border.
But that risks undermining Beijing's attempts to play more of a role as a great power in the region.
'This is a big dilemma for China, but it would be unrealistic to expect China to line up behind South Korea so soon after Kim Jong-il's visit,' said Shi Yinhong , a professor of international security at Renmin University who follows Korean affairs, Reuters reported.
'The price that China will pay will be its regional influence, especially over South Korea. It will have some impact on that influence ... now regional governments may feel that Chinese foreign policy is out of balance.'
Other analysts have noted that China is unlikely to be convinced by the multinational investigation and Seoul could struggle for sensible options if China exercises its veto over any fresh UN Security Council move, as is widely expected.
China's leaders are widely believed to have pressured Kim behind the scenes during a hastily-arranged visit to Beijing two weeks ago but, publicly at least, offered no direct criticism. The US and South Korea expressed concern over the trip.
The North, of course, also has a wide range of military options, from artillery and missile tests to the bigger step of a third test of a nuclear weapon.
China is also aware that the crisis has so far pushed the South Koreans and the US even closer together. Both Seoul and Washington, traditional allies, have reported exceptionally close discussions over the best way forward.
While Washington will be wary of unwitting provocations, it has so far been active in pushing for a firm response. Putting North Korea back on its list of terrorist sponsoring nations - an act which could further isolate the country economically - is one possibility.
The White House issued a strong statement of condemnation but stopped short of specific measures that could be taken.
'This act of aggression is more instance of North Korea's unacceptable behaviour and defiance of international law,' White House spokesman Robert Gibbs said. 'Such unacceptable behaviour only deepens North Korea's isolation.'
US Secretary of State Hillary Rodham Clinton is due to arrive in Beijing tomorrow before heading to South Korea and Japan in her fifth trip to Asia - a trip now set to be dominated about finding common regional ground on an adequate response to South Korean concerns.
At this point the situation appears to highlight divides that underpinned the once-vaunted six-nation effort to denuclearise North Korea - talks now effectively frozen.
While China's role in dealing with South Korea, Japan and the US as well as Pyongyang in the effort raised early hopes of ground-breaking co-operation, it is still operating with habitual caution and secrecy.
'Our Chinese colleagues worked hard to foster co-operation and dialogue but they still never gave much away about North Korea,' said one US official close to the process.
'The old ties and duties went too deep, I guess. They never shared much about their views of North Korea's strategies or intentions or other thoughts on the leadership.'
That lingering mistrust is likely to swing into closer focus in the coming days and weeks as the region attempts to get control of a situation that has only unpredictability at its core - the strange regime of Kim Jong-il.
Additional reporting by Kristine Kwok
Cold war hangover
North and South Korea have remained technically at war since the Korean conflict ended with an armistice in: 1953