Subject and purpose of work: This study examines how the strategic competition between the United States and China contributes to geoeconomic fragmentation in Southeast Asia. It also generates divergence in ASEAN member states’ external economic alignments, with effects on ASEAN-centered regional integration frameworks such as the RCEP. Materials and methods: Using a qualitative process-tracing approach, the study analyzes the Philippines as a critical case, focusing on its withdrawal from Belt and Road Initiative (BRI)–associated infrastructure financing, and its delayed trajectory toward accession to the CPTPP. Results: The findings indicate that while RCEP remains institutionally intact, geoeconomic fragmentation increases coordination costs and hinders ASEAN’s ability to maintain a coherent external economic posture, thereby limiting the depth and effectiveness of ASEAN-centered regionalism under conditions of rivalry. Conclusions: The findings demonstrate that ASEAN-centered integration can remain institutionally intact while becoming increasingly constrained in depth and coherence, thereby reframing resilience not as institutional durability alone but as the sustained alignment of member-state strategies.