This article examines the expansion of membership in ASEAN which has occurr
ed during the second half of the 1990s, and identifies the factors behind t
his process, with particular attention devoted to the efforts aimed at impl
ementing the conflict management mechanisms of ASEAN on a wider regional le
vel. The study takes as its starting point the rapprochement between the or
iginal member states of ASEAN and Vietnam and Laos, which began during the
second half of the 1980s and gained momentum following the resolution of th
e Cambodian conflict in 1991. The first half of the 1990s was characterised
by the gradual acceptance by other Southeast Asian countries of ASEAN's co
de of conduct for inter-state interaction. This paved the way for the acces
sion to full membership in ASEAN of Vietnam in 1995, of Laos and Burma in 1
997 and of Cambodia in late 1998. Given the considerable discrepancy in the
level of economic development between the new and old members of ASEAN, th
e economic motivation for expanding ASEAN would be to facilitate foreign in
vestment in the new members and open new markets for exports within an expa
nded ASEAN Free Trade Area (AFTA). The article argues, however, that the po
litical and security considerations are more important in explaining why th
e original members embarked on the process aimed at bringing all 10 Southea
st Asian countries into ASEAN. It is in this context that the policy of con
structive engagement and peaceful management of inter-state conflicts comes
into play.