Since the 2015 World Education Forum, Global Citizenship Education (GCE) as a ‘global idea’ has been widely disseminated to local schools in Korea. GCE Lead Teacher Program has been a major state-led initiative for school change. Informed by Fullan's model for change, we explore what happens ‘on the ground’ when the state introduces GCE through a conventional top-down model at a fast pace and with strong enthusiasm. Using qualitative data, we delve into problems and potentials in teachers’ practices of GCE at schools in the context of a state-led GCE model. Implications for research, practice, and policy are discussed.