ASEAN has politically constructed the region in ways that reflect the idea of an ASEAN community, of SEA as a single political, economic and social space. Although it is not identical with SEA, it is difficult to talk about SEA without referring to ASEAN. But ASEAN is but part of the SEA story. While ASEAN’s leaders project SEA as a single and integrated community, other narratives exist. Many people remain marginalized even excluded in the discourse and practice of regionalism throughout ASEAN. Non-state actors seek roles in constructing SEA. ASEAN framework building has motivated civil society groups to advocate for a more integrated SEA. They emphasise a people-oriented rather than institutional or elitist framework. In addition, business communities play important roles in bringing SEA people closer together, and their contribution should not be neglected. WP5’s central theme is the role played by ASEAN and grassroots movements in integrating SEA.