Bounded middle-power agency and minilateral potential in the Indo-Pacific: a domain-sensitive analysis of Korea–ASEAN cooperation

Minilateral cooperation has become prominent in Indo-Pacific security governance, yet debate remains centred largely on great-power coalitions and strategic competition. Less attention has been paid to how capable non-hegemonic states organise selective cooperation within ASEAN-centred regionalism or why similar pressures generate different institutional forms across issue domains. This article develops a domain-sensitive framework for assessing the institutional forms and minilateral potential of middle-power-facilitated cooperation. It applies the framework through a structured comparison of Korea–ASEAN cooperation in cybersecurity, supply-chain resilience, and defence-industrial collaboration. The findings identify institutional differentiation and redirection across domains rather than a linear decline in cooperation. Cybersecurity shows the strongest evidence of recurrent multi-actor capacity-building, but these activities remain embedded in inclusive ASEAN-led mechanisms. Supply-chain cooperation combines bilateral industrial ecosystems and ASEAN-wide frameworks with planned plurilateral capacity-building, while defence-industrial cooperation remains dominated by platform diffusion and bilateral production and sustainment relationships. Regionally dispersed bilateral or multi-actor activity therefore does not itself constitute minilateral governance. The analysis identifies a potential pathway to regional order-building through institutional layering, but direct effects on preparedness, vulnerability reduction, dependency management, and institutional diffusion remain unverified. Korea’s middle-power agency is therefore best understood as bounded facilitation rather than established minilateral convening.