Asean needs to find new areas and fresh commitment to work together so that the grouping can remain central to the region's architecture and future.
Prime Minister Lee Hsien Loong said this yesterday, as he made the point that the grouping can only maintain its centrality "if it is a substantial endeavour, if its members see value in the shared enterprise".
Spelling out the challenges facing the grouping, including worrying trade tensions between the United States and China, PM Lee set out why Asean has to speak in a collective voice to be effective as it reacts to these major external trends.
If each member state were to fend for itself and go its own separate way, the grouping would be less relevant to its own members and to other powers, he said at the opening ceremony of the 32nd Asean Summit, which Singapore is hosting as this year's chairman.
"Individually, the Asean member states will find it hard to make much impact on their own. But when we speak in one collective Asean voice, we can be effective," said PM Lee.
This is why it is important for Asean to redouble its integration and community-building efforts.
Individually, the Asean member states will find it hard to make much impact on their own. But when we speak in one collective Asean voice, we can be effective.
PRIME MINISTER LEE HSIEN LOONG
At the summit, Asean leaders also discussed regional developments.
On the disputed waters of the South China Sea, PM Lee called the situation "relatively calmer".
But negotiations between Asean and China on a code of conduct in the South China Sea, which began last month, will "take some time".
He outlined the various difficulties involved, such as whether the code of conduct would be legally binding, how to define exactly what Asean and China were disagreeing about, and should the code be binding or legally binding - how these issues will be arbitrated, where and by which authority.
"These are all very difficult issues. They will take a long time to crystallise, never mind agree upon," he said.
"But it's better that we spend our time talking about the code of conduct constructively... than not to try and to just take unilateral measures that just lead to escalation and unpredictable consequences."
During the summit, Myanmar briefed its fellow Asean members on the situation in its Rakhine state, from where more than 700,000 Rohingya Muslims fled amid a military crackdown.
At a press conference afterwards, PM Lee said that Asean encourages Myanmar and Bangladesh to continue to carry out the voluntary return of displaced persons in a "safe, secure and dignified way without undue delay".