Cambodia will fulfil its last major obligation as this year's Asean chair on Nov 18-20, when it hosts the annual Asean Summit and seventh East Asia Summit (EAS).
The EAS in particular will provide Cambodia with the opportunity to restore some of its credibility after the public embarrassment of the Asean Ministerial Meeting (AMM) in July.
On that occasion, Cambodia used its prerogative as Asean chair to block the inclusion of any mention of the South China Sea maritime disputes in the joint communique at the end of the meeting, resulting in the organisation's first-ever failure to release such a document.
That failure cast significant doubt on Asean's ability to evolve and tackle tough issues. It also caused troubling allegations, especially from Vietnam and the Philippines, that Cambodia had placed its close relationship with China above the interests of its fellow Asean members.
All the damage wrought in July will not be fixed in three days in November.
But if the EAS goes demonstrably better than the AMM did, Cambodia's image will have a chance to recover and some of the Asean sceptics will be quieted.
A successful EAS, and by extension a stronger regional framework in the Asia Pacific, is in the interests of all EAS members, including the US.
The key will be supporting Cambodia as an effective chair.
The EAS was only established in 2005, but its membership and mission are already of great significance for regional architecture. Encompassing all 10 Asean members plus Australia, New Zealand, India, China, South Korea, Japan, Russia and the US, the EAS boasts the most effective membership of any Asia-Pacific organisation.
It does not split Asean as Asia-Pacific Economic Cooperation does, or exclude major powers as Asean+3 does, or contain too many disparate members to be effective, like the Asean Regional Forum.
Leaders at this year's EAS will likely find common ground on green growth, the adoption of a Declaration on Resistance to Antimalarial Medicines and various means of boosting Asean connectivity. Cambodia is eager to see its chairmanship accomplish these and other relatively easily achievable goals.
However, its tenure as chair will be judged not on laudable but non-contentious deliverables. Instead, it will be judged on how willing and able it is to oversee an honest, balanced and productive discussion on the tough issues that divide members.
The 2012 EAS agenda will include a number of such topics. Foremost among these will be maritime security and the ongoing disputes in the South and East China seas. Some members would rather avoid these topics, which have turned contentious at nearly every major Asean-led meeting in the last three years.
But Vietnam, the Philippines and Japan are almost certain to raise them, and others, the US included, will not keep quiet once the issues are tabled.
The summit will also include side meetings on two different visions for economic integration _ the Regional Comprehensive Economic Partnership favoured by China, and the US-led Trans-Pacific Partnership.
Strong Cambodian leadership and a flexible, effective response to any lack of consensus on key issues will alleviate doubts about Asean unity and efficacy. That will allow the organisation to cement its place at the centre of regional political, security and economic structures.
The most important role of the chair is the prerogative to set the agenda at the summit. Cambodia cannot prevent the Philippines or Vietnam from raising the South China Sea issue, for instance, but it can take the initiative and place that discussion where it will be most effective.
Where that is, whether at the end of discussions, after the low-hanging fruit have created an environment of mutual trust and understanding, or sandwiched between expected accomplishments to soften the blow, will be up to Cambodia.
But what it cannot attempt is a repeat of its behaviour at the AMM, where it refused to include any of the tough issues on the agenda and became upset when its counterparts refused to play along.
The role of the chair must be to guide discussions, not to block or react to them.
Cambodia follows the groundbreaking chairmanships of Vietnam in 2010 and Indonesia in 2011, who made a successful Asean year a hallmark of their foreign policy and a coming-out party for their role on the regional and global stage.
The unfortunate side-effect of such successes, which pushed the bounds of Asean norms and sought to bring the organisation closer to its potential place as regional fulcrum, is that the bar seems a bit too high for those that follow. Brunei is set to take over the chairmanship in 2013, followed by Myanmar in 2014 and Laos in 2015.
Cambodia's performance at the AMM cemented the perceptions of those who said fecklessness and division were the inevitable outcomes of Asean's smaller and less developed members occupying the chair.
Cambodia must set a precedent for how upcoming chairs can engage contentious issues and manage tensions between the region's larger players.
This is especially true of Cambodia's handling of China. Cambodia, like Myanmar and Laos, is heavily dependent on Chinese aid and investment. And, like them, it lacks a deep strategic relationship with the US to help balance its dependence on Beijing. The result is that Cambodia is more prone to Chinese pressure than are most Asean members.
Cambodia must communicate to China, by words and actions, that it cannot manipulate the Asean chair into overrepresenting Chinese interests.
This will be a tall order, particularly as the EAS will take place amid a highly sensitive leadership transition in Beijing. Cambodia will have to allow its neighbours to discuss the contentious issues important to them, regardless of Chinese objections, in an honest and transparent manner. But it will also have to guide the discussion to avoid provoking China unnecessarily.
Placing difficult issues like the South China Sea squarely on the agenda ahead of time is critical. These issues will be raised regardless, and leaving China feeling ambushed serves no one's purposes.
If successful, a strong Cambodian chairmanship will be a vital first step toward convincing China to work within existing regional structures like the EAS, and to do so transparently, rather than trying to exploit its bilateral relationships to undermine Asean unity.
The US and its partners can play a supportive role in this effort. They must state their positions on issues of contention, especially the importance of international law and peaceful resolution to maritime disputes, but must at the same time not be seen as attempting to ostracise China at the summits.
The overall goals of the United States and all EAS members must be to voice their positions openly and honestly, support Cambodia as the chair, and not force it into a position of choosing between China and the rest.
A successful Cambodian leadership in November could have a significant impact on the effectiveness of Asean for years to come. If the summits were to face difficult issues honestly and yield measurable progress toward regional goals, the debacle at the AMM would become a footnote.
Cambodia would help restore confidence in Asean's effectiveness and centrality to regional architecture. Just as important, it would set the stage for Brunei, Myanmar and Laos to oversee their own successful years as chair.
The next few years could prove a watershed for Asean in its quest for centrality in regional architecture. It is the best chance for a multilateral vehicle to promote peace, stability, and continued economic development in the region. All members of the EAS, China and the US most of all, should welcome this goal and support Cambodia in its efforts to bring it a step closer to reality.
Gregory Poling is research associate with the Chair for Southeast Asia Studies at the Center for Strategic and International Studies in Washington, D.C. Alexandra Sander is a researcher with the Chair for Southeast Asia Studies. The article originally appeared in the Pacific Forum CSIS Pacnet series.