Here's the bad news: one of the group's founding members, Singapore, thinks it risks becoming irrelevant.

Singapore is right: Asean should not deceive itself that its diplomatic feat reflects real regional clout. The group needs to focus on internal reform to acquire the influence it deserves.

That is not to deny the diplomatic achievement. Bangkok provides an unprecedented opportunity for dialogue between the foreign ministers of North Korea, the US, China, Japan and Russia. An isolated North Korea may thus move further towards closer integration with the outside world. Because of its informal nature, Asean's regional security forum is an ideal place for North Korea to begin building new international relationships. The task for Asean members will be to maintain pressure for a firm commitment to restrain missile development and proliferation.

North Korea must understand that there is a limit to economic assistance while the missile question is unresolved. But help should be available if it agrees to co-operate. For example, it may be time to begin more serious consideration of North Korean membership in the International Monetary Fund, World Bank and Asian Development Bank.

Tangible progress in these areas is unlikely in Bangkok. What is certain is that the mere fact of North Korea's presence will be grounds for a great deal of fuss. This should not obscure the risks that Asean is becoming marginalised.

The group sets great store by its intensified collaboration with Japan, China and South Korea. But the need for such outreach underlines the fact that Asean seems unable to achieve much on its own. Its attempt to set up a free trade area looks less convincing because of Malaysia's determination to continue protecting its car industry. It has again failed this year to resolve the important issue within its own borders of haze emanating from forest fires in Indonesia.

This weakness is a pity because a strong Asean would offset China and be a useful part of the power balance in the region. If Asean wants to play a serious role, it must push harder for trade liberalisation, which will attract outside investment. And its members must display a more determined approach to problems - like the haze - that divide the group.

It's good that North Korea is in Bangkok as a guest. But that is no substitute for efforts to build greater cohesion among Asean's own membership.