Indonesia’s stewardship of Timor-Leste’s accession to the Association of Southeast Asian Nations (ASEAN) is not just about regional solidarity. These initiatives reflect a strategic pivot toward sustainable development, regional integration and institutional capacity-building, aligning with ASEAN’s benchmarks and Indonesia’s mentorship goals. These reforms not only signal Dili’s readiness for ASEAN membership but also underscore the urgency of embedding Timor-Leste’s development within regional frameworks that ensure continuity and accountability. To counterbalance this, Jakarta’s task is to offer a compelling alternative: an “ASEAN Development Corridor” linking Nusa Tenggara Timur with the Oecusse Special Zone via a free-trade border arrangement. Together, Jakarta and Canberra can ensure that Timor Leste’s ASEAN membership is not a symbolic milestone but a catalyst for genuine development, regional stability and shared prosperity.