Instrumentalizing Migration in an Era of Demographic Crisis: Policy Beliefs and Punctuated Equilibria in South Korea’s Vietnamese Migration Policy

South Korea faces a severe demographic crisis characterized by an unprecedented decline in its total fertility rate, transforming labor migration governance from routine administration into a contested policy arena. Focusing on the Employment Permit System (EPS) and Vietnamese labor flows—one of the largest sending-country cohorts—this study examines how competing policy beliefs shape migration governance and contribute to periodic policy shifts. Employing an integrated framework combining the Advocacy Coalition Framework (ACF) and Punctuated Equilibrium Theory (PET), the analysis traces policy dynamics using documentary evidence, including official statistics, bilateral memoranda of understanding (MOUs), parliamentary records, and policy white papers. The findings identify competing instrumentalist growth and nativist closure orientations that structure policy debate while varying across specific dimensions of migration governance. Policy stability has been periodically disrupted by shifts in policy image and political attention, most notably the 2012 restrictions associated with escalating non-return concerns and the post-2020 expansion of EPS admissions linked to demographic-emergency reframing. The study concludes that continued reliance on temporary migration creates an instrumentalization trap: expanding labor recruitment without corresponding changes in opportunities for long-term residence and social incorporation limits migration’s capacity to address structural demographic decline.