The Association of Southeast Asian Nations, or Asean, was established on 8 August 1967 in Bangkok, Thailand, with the signing of the Asean Declaration by Indonesia, Malaysia, Philippines, Singapore and Thailand. Since then, membership has expanded to include Brunei, Myanmar, Cambodia, Laos, and Vietnam. Its aims include accelerating economic growth, social progress and cultural development of its member states and the protection of regional peace and stability.
Unruly Asean not playing Beijing's game on territorial disputes
Even with client state Cambodia chairing the bloc, China finds it hard to keep members in line on how to deal with territorial rows
The frustration and sarcasm were evident as Foreign Ministry spokesman Qin Gang outlined the "mathematics" at play this week behind China's troubled relations with the Association of Southeast Asian Nations.
First, Qin said, one had to add up Asean's East Asia Summit - "10 plus eight"- the 10 nations of Asean and eight other powers, including China and the United States.
Then, he said, there was "another mathematics" within Asean itself. "It's 10 minus two," Qin noted, a clear swipe at the Philippines and Vietnam, two nations Beijing fears are driving the internationalisation of its South China Sea disputes.
"And which is bigger?" he asked rhetorically on the sidelines of this week's summit in Phnom Penh.
Unfortunately, Asean insiders are warning that the political calculus now under way is not quite that simple, as Southeast Asia finds itself drawn into the wider Sino-US strategic rivalry.
China is set to face mounting challenges from the grouping over the South China Sea as Cambodia's controversial year as Asean host and chair comes to an end. As difficult as it may have been, Cambodia's year may be as a good as it gets for Beijing - in the short term at least.
Cambodia - a long-time benefactor of Chinese aid and development efforts - has been accused of doing China's bidding in recent months in working to stall Asean's intensifying focus on maritime territorial disputes. China, it must be remembered, wants ultimately to settle specific disputes with individual claimant countries - something most analysts believe would give a clear advantage to Beijing.
First, Cambodia oversaw the historic breakdown of the annual Asean foreign ministers meeting in July, when arguments over how to handle the South China Sea sparked unprecedented rancour. Asean has for decades cherished consensus above all else. For the first time in 45 years, the ministers could not even produce a routine communiqué.
After that debacle, leaders headed to Phnom Penh determined to push progress on a binding code of conduct with China to better govern tensions, yet still determined to not let the issue swamp a raft of economic, trade and integration issues.
It was not to be. An announcement on Sunday from host Cambodia that Asean's leaders had formally agreed not to internationalise the issue "from now on" sparked a flood of questions. Asean-China talks would be the sole forum, spokesman Kao Kim Hourn added.
Given that leaders - including US President Barack Obama and allies from Japan, the US and Australia - were converging on Phnom Penh determined to raise the need to lower South China Sea frictions, it was a remarkable agreement, and a victory for Beijing's backroom lobbying.
But the consensus hailed by Cambodia lasted less than a day. The Philippine delegation, led by President Benigno Aquino, cried foul, warning there was no such deal and insisting on its rights to seek international redress if it felt that its national sovereignty was threatened.
Asean unity was again in tatters and the South China Sea, it seemed, was back on the wider global agenda, despite Beijing's efforts. Other Asean envoys confirmed there was no formal agreement to limit discussions, even as they expressed a desire in meetings to keep tensions from stalling progress on other topics.
Ultimately, few insiders were surprised at the turn of events. Cambodia's entrenched Prime Minister Hun Sen - a former Khmer Rouge commander now seen as East Asia's last strongman - is not known for his diplomatic subtlety, after all.
As envoys drove up to the meeting venue at his Chinese-built Peace Palace, they found the walls draped with banners hailing the "long life" of Cambodia's relationship with China and Premier Wen Jiabao . The banners would stay all week, even as 16 other leaders made formal calls on the palace.
Those who looked closer would notice the ranks of soldiers in the surrounding streets with the latest Type 097 Chinese assault rifles and Chinese-made motorbikes.
Local papers were filled with news of a US$50 million aid deal pledged by Wen in side meetings with Hun Sen, a pledge on top of US$500 million offered in September and all part of an extensive development, economic and trading relationship that has made China Cambodia's most important international partner.
"Hun Sen's certainly done the business for China this year," one Asean envoy said. "But it has only brought Beijing delay, not outright success. It has also inspired a renewed determination to get talks back on an even keel and get something workable moving. Everyone is wanting to pick up the pieces and move forward."
While the Cambodia relationship will remain deeply strategic, Chinese officials and scholars are already noting challenges ahead as the revolving Asean chairmanship turns to Brunei.
The tiny oil-rich sultanate - Southeast Asia's last absolute monarchy - represents a potentially tougher nut. While one of Asean's quieter players, it is one of China's four rival claimants to areas of the South China Sea.
Already Singapore - which is keen to see progress next year on the code of conduct - and other nations have been discreetly helping Brunei get ready for its return to the diplomatic spotlight.
Another potential complication is the revolving door of the officially neutral post of secretary general of Asean - a position of little formal power but considerable profile.
Former Thai foreign minister Surin Pitsuwan handed over the baton this week to Vietnamese diplomat Le Luong Minh, who starts a new five-year term.
Minh, who has extensive UN experience, is expected to more forcefully keep Asean's push for the code firmly on the agenda.
Surin has at times appeared reluctant to get into the details on South China Sea tensions, beyond bland calls for unity. As temperatures rose this week, he backed out of press appearances.
Minh will risk criticism, however, if he too brazenly peddles Hanoi's line against China.
The post remains something of a work in progress and presents an opportunity for Minh to turn it into something more substantial. As some scholars have noted, Asean needs more of a general than a secretary.
The issues he must confront are nothing less than a battle for Asean's soul. Once again it finds itself at the centre of great power rivalries as it did at the height of the cold war. And no one, of course, wants to revisit that blood-soaked era.
In the rhetoric of Washington, its re-engagement across Asean is part of an effort to "shape" China's rise, forcing it to conform to international norms. With considerable discretion, it has buttressed efforts among Asean countries to co-ordinate and organise diplomatic responses to Chinese challenges.
While the Philippines stood up publicly this week, others were helping in the background, for example.
From their side, Chinese officials and some scholars made it clear that they were determined to shape Asean's rise in return. China must not be threatened, contained or challenged in its own maritime backyard, and bilateral disputes must not be the subject of outside meddling.
As Peking University's Professor Zha Daojiong said recently, China had no interest in a divided Asean, but it had to be careful that, over the long term, Asean did not evolve like an increasingly assertive and interventionist Arab League.
Zha said China had a strategic interest in an Asean that was strong, united and able to lead regional meetings with outside powers, but it must keep to its long-term agenda of peacemaking and conflict avoidance, rather than anything more assertive.
Zha said China would never want to see the grouping "championing military action within itself, or against others outside".
Some in Asean clearly want China to be more aware of its own might, however, and back off recent actions in the name of calm relations.
As he returned to Manila after issuing an international plea for urgent action, Aquino insisted that his government still wanted China "to set the example of wise and peace-seeking leadership", Bloomberg reported.
"Our region is very diverse and its harmony can easily be disrupted by sheer political, military or economic might," he said.
The debates, then, roll on, with the South China Sea, claimed by China in virtually its entirety, at their core.
Just four years ago, China had successfully kept Asean nations officially quiet on the subject. The events of the last week have shown that, despite considerable efforts, the calculations are now much more complex.