Challenging the conventional processes of conceptualising the European Union as an actor, this study provides a timely and in-depth analysis of EU-ASEAN relations which contests the use of power as the basis of such conceptualisations. It assesses the EU's actorness by analysing its attempts to promote its regionalism experience to ASEAN. Three aspects of regionalism - economic integration, institutionalisation and political norms - are analysed using data collected from officials and researchers connected to these regions. In doing so, this compelling volume shows that the effectiveness of the EU's aim to diffuse these norms is predominantly determined both by ASEAN's perception of the EU as an actor and its consideration of the EU's regionalism experience as relevant to ASEAN