The ASEAN member states have rapidly increased their global share of science and engineering knowledge production during the past 20 years, from 0.65% in 1996-2000 to 2.8% in 2016-2020. However, the growth in knowledge production has been unequal, and has occurred during different periods of time in different member states. The growth in knowledge production has also been accompanied by significant shifts in the knowledge production profile of individual ASEAN member states, both in terms of quantity and quality, and a transformation of their international research collaboration networks. Using a new open-source dataset of nationally aggregated scientometric indicators extracted from the Scopus database, and applying the concept of revealed comparative advantage, the study documents how ASEAN regionalism is fading and how it is being replaced with a broader Asian regionalism in international research collaborations, in which some, but not all, ASEAN member states are participating.