In the 2020s, the Korean Peninsula seems to have further alienated its desire for peaceful reunification due to the North Korean nuclear threat that has continued for the past 20 years. However, clues can be found to solve this crisis in the history of the last democratization movements, which have always pursued a unification movement with the change of dictatorship. This paper examines the nationalist ideal that has always accompanied Korea's democratization efforts, identifies the connection between the democratization movement and the unification movement, and presents contemporarily significant points based on the results. For the purpose of this study, the researcher introduces the traditional security view that has relied on military power by considering the South Korean people's sense of unification in the midst of the North Korean nuclear crisis in the 2020s and the realist opinion that leads the cause and feasibility of unification on economical terms. In addition, this research examines the pattern of the post-Cold War nationalist integration spirit that appeared in the unification movement process after the democratization movement, and highlights the connection point of the two major movements and their value of the time. This study has found that students and citizens who participated in the pro-democracy movement argued for nationalistic ideals against foreign intervention while resisting the authoritarian government's suppression of the pro-democracy movement in the name of the US-backed anti-communist line. This research is significant in that it emphasizes that continuous democracy practice is a key element of security in addition to military power by linking the two major movements ideologically.