Acharya lists for four 'areas of accomplishment' to explain this. First, ASEAN's relative longevity as the pre-eminent regional organization. Second, no member states have had serious armed confrontations with each other. Third, ASEAN helped bring peace to Cambodia and integrate Vietnam. Fourth, it was instrumental in getting China and other extra-ASEAN powers to engage in its regional multilateral processes.

John Ravenhill assesses these four points in his Review of International Studies article, 'East Asian Regionalism: Much Ado About Nothing?' (abstract). He points out that longevity is a 'double-edged sword' as it invites comparisons with younger organisations that have managed to do more. I suppose ASEAN doesn't fare too badly when compared with the posturing and theatrics at the United Nations General Assembly but Ravenhill's point is well-taken when you think of the Shanghai Cooperation Organisation's joint military exercises and Inter-Bank Council or the African Union's peacekeeping missions.

While it is true that no ASEAN member state has gone to war with another, Ravenhill finds it impossible to prove that ASEAN was the cause of this 'in a non-tautological manner' as opposed to, say, the Pax Americana. He goes on to cast doubt on Acharya's claim by citing studies by Tobias Nischalke and Christopher Roberts (PDF 1|2). The former finds that ASEAN norms have little impact on member states' behaviour while the latter's systematic survey of grassroots and elite opinion in ASEAN found low trust in others to be good neighbours; those survyed in Singapore and Thailand 'were least certain that there would be no intra-ASEAN conflict in the next twenty years.' When you look at the long list of problems and close calls noted by Andrew Tan's Intra-ASEAN Tensions (partial PDF), one might say that those surveyed were just being realistic.

On the Cambodia issue, Ravenhill notes its early success but ultimate conclusion due to 'great power intervention under UN auspices' as the deciding factor, citing Michael Leifer's ASEAN and the Security of South-East Asia (which I have not read). IIRC the chapter on the Cambodian war in Leifer's book, Singapore's Foreign Policy (which I have read), was even less laudatory about the early phase, reminding us of ASEAN's support, at the tacit behest of China and the US, for the murderous Khmer Rouge.

Ravenhill is also cautious about the weight that should be given to ASEAN with respect to China's accession to the Treaty of Amity and Cooperation (TAC). He argues that, during that period, China had been going all manner of global organisations to claim its rightful place in the world and regional organisations to balance Japan. Furthermore he notes the reservations appended to the TAC accessions of Australia, South Korea and Japan.

He goes on to assess ASEAN economic integration and functional cooperation, noting how 'there is more than a little irony when [member states] are willing voluntarily to sign on to these agreements with extra-regional actors but maintain a reluctance to commit themselves to similar agreements within ASEAN itself.' One only has to look at the rather lacklustre progress towards complete removal of all tariffs on non-scheduled goods in compliance with AFTA's 2010/15 deadline much less cutting down the bloat in the Sensitive and Highly Sensitive schedules.

Ravenhill concludes that ASEAN has been far less effective than even its own member states' arrangements with extra-regional partners, mainly due to unclear and unenforceable obligations compounded by ineffective dispute settlement mechanisms. While The Cable pokes fun at the lack of substance that the Obama administration's delegation will be bringing to the agenda and negotiation table, one could say that they are merely showing deference to ASEAN by doing things the ASEAN Way.