The Association of Southeast Asian Nations is often criticised by outsiders for its slow decision-making. But through consensus, its 10 racially and religiously diverse members have created a measure of unity in a region that is fraught with uncertainty. Amid rising tension over disputed territorial claims in the South China Sea with China and a resurgence of strategic interest by the US, there has never been a more pressing time to guarantee stability. The failure of an annual meeting of foreign ministers to produce a joint communique bodes poorly for negotiating the considerable challenges ahead. Self-interest has driven a wedge through Asean. The chair of the meeting, Cambodia, put its alliance with China ahead of the regional grouping. Heavy lobbying by Beijing and Washington all but assured a split. There are now doubts as to whether Asean can deal with the region's big-power rivalry, which goes to the heart of its solidarity and unity and the co-operation of its members. While overshadowing efforts to push progress on Asean's plans for an economic community in 2015, it could also affect a most urgent matter - the drafting of a code of conduct with China to govern disputes in the South China Sea. Never before in Asean's 45-year history has there been so much discord that the ministerial meeting was unable to draw up a joint communique. Differences were always overcome to reach a compromise in what is known as the 'Asean way'. Too much is at stake for past practice to be shunned in favour of the interests of a single member. If the grouping is to be effective and move confidently forward, nations have to work together towards a shared vision. The rivalry between China and the US muddies the complexity of the South China Sea disputes. But the various territorial and historic claims of four of its members, mainland China and Taiwan will not be resolved quickly and should not be allowed to get in the way of Asean's ambitions. The grouping has to review the events in Phnom Penh and put them behind it so it can return to the path of cohesion and unity.