Abstract
South Korea demonstrated its ability to respond effectively with rapid policy measures and implementation in the early stages of the pandemic. However, at the end of second year of the pandemic, South Korea reached a peak in its number of daily new cases. Why didn't South Korea maintain the initial successful performance? To answer the question, this study examined South Korea's pandemic response process through Complex Adaptive Systems (CAS), focusing on actors' behavior according to the phase transition. We found that the South Korean government failed to interact with the rapidly evolving public due to the different evolving pace. Dissonance between the government and the public resulted in distrust, fatigue, and resistance to the government's policy among people. From the case study of South Korea, this study emphasizes that not only individual governments, but also the international community, should anticipate and interact with the rapidly evolving public to prepare for the pandemic and post-pandemic era.