Managing strategic autonomy amid the transition in U.S. grand strategy: South Korea and the composite equilibrium model

Abstract

This study examines how the transition in U.S. grand strategy is reshaping the strategic environment surrounding South Korean foreign policy and proposes a Composite Equilibrium Model of Strategic Autonomy as an analytical framework for analyzing and managing these changes. The 2025 U.S. National Security Strategy reconceptualizes strategy as a process of strategic prioritization and institutional coordination rather than the pursuit of a fixed policy orientation. By emphasizing economic security and institutionalized burden-sharing, the NSS redefines alliances as frameworks of functional cooperation rather than automatic military guarantees. These developments generate structural pressures for South Korea that transcend the conventional binary between alliance deepening and hedging. In response, this study conceptualizes alliances and hedging as interdependent strategic variables that can be calibrated through institutionalized policy adjustment. Strategic autonomy is therefore understood not as a fixed condition but as a cumulative outcome emerging from the interaction between these variables over time. The Composite Equilibrium Model provides a framework for explaining how middle powers coordinate alliances and hedging to sustain strategic autonomy under structural constraints amid the transition in U.S. grand strategy.