The paper analyzes why South Korea, a war-tom and poverty-stricken country, succeeded in building a modem state in a single generation under the most trying circumstances. Despite its remarkable success, there are conflicting views on contemporary Korea: common liberal perspectives tend to focus on its deviances from democracy. The author develops a theoretical perspective on nation building which assumes that a new nation lacks the basic infrastructure of a modem state and therefore the primary task of leadership is to build this infrastructure security, economy, and democracy. It is assumed that many constraints as well as multiple challenges exist in nation building, but a step-by-step approach is necessary. In terms of a comparative historical perspective based on the nation-building of early modernizers, those nations experienced a centralization of power, a buildup of a standing army and economic growth, and democratization occurred gradually. The paper then analyzes how South Korea's nation building is similar to those early modernizers in terms of sequential achievement in the order of security, economic growth, and democratization. Witnessing a looming failure of the U.S. policy of democracy promotion in Iraq, the approach has important theoretical implications for those who struggle with the lingering problems of many Third World nations.