This dissertation is a theoretically grounded empirical study aimed at shedding light on the multiple dimensions of South Korean President Kim Dae-jung's Sunshine Policy of engaging North Korea. It questions the ontological viability of conventional strategies and theories of engagement and produces a framework of comprehensive engagement based on realist, liberal and, most importantly, constructivist approaches. The study focuses on identifying the new tools of engagement employed by South Korea's policy elites, who created a social environment for South Koreans' shift of identities vis-a-vis North Korea in the course of implementing this engagement policy. To support the thesis of a momentous shift in identities as a result of the Sunshine Policy, this study uses a wide range of interviews with policy elites and sets of opinion polls published by news organizations and government agencies, while at the same time analyzing the policy from a theoretical and historical perspective. In order to provide concrete evidence of the identity shift, this dissertation analyzes three major policy issues during the Kim administration: North Korea's improvement of diplomatic relations with Western powers; the Hyundai Business Group's Mt. Kumgang tourism project and its link to the inter-Korean summit in June 2000; and North Korea's revelation of a nuclear weapons programme in October 2002. The key research findings of this study are as follows: first, the Sunshine Policy, implemented by South Korea's policy elites, who projected North Korea as a 'partner' or a 'brother', enabled a majority of South Koreans to develop positive identification with the South's enemy, as defined by the National Security Law; second, the policy played a significant role in preventing crises and maintaining the political status quo on the Korean Peninsula; and third, the policy laid the groundwork for a new era of inter Korean economic cooperation and integration.

The main purpose of this thesis is to explore the complex relations between South Korea's national security, state identity, and engagement policy towards North Korea over the years, with the primary temporal focus on the Kim Dae Jung administration (1998-2003) and in terms of the conventional and critical constructivism in International Relations (IR). Related to the South's engagement with the North, this thesis also aims to critically examine Pyongyang's Korean nationalism and National Cooperation (Minjok Gongjo) Doctrine directed at South Korea (and even the United States) at the dawn of the 21 century. Before embarking on the above empirical analyses, the thesis theoretically considers constructivist security studies as an analytical framework for examining Korea's identity politics during the Kim Dae Jung administration. The thesis also considers the historical context of South Korea's national security until the late 1990s, just before the advent of the Kim Dae Jung administration in 1998.

This thesis is a history of South Korean policy towards North Korea and its general foreign policy at the time of fluctuation of relations between the allies, the Republic of Korea and USA, between 1968 and 1979. The thesis shows how American East Asian policy and South Korean people‘s aspiration for the reunification and democracy of Korea affected Park Chunghee‘s Cold War strategy. After Park Chunghee failed to find a common ideological foundation with the Americans, the South Korean leader started to re-consider the inter-Korean problem and ROKUS relations in realistic term. In the late-1960s and early 70s, Seoul shifted from antagonism toward Pyongyang to negotiation with the North Koreans in order to support American rapprochement with China. But simultaneously, the Park regime established the authoritarian state and resisted the American influence on its foreign policy. With regards to the ROK-US rift, the thesis points to their misperceptions between the South Korean and American leaders in their war in Vietnam and East-West reconciliation. In addition, this thesis also shows how South Korean nationalism and liberal movement affected Park Chunghee‘s policy. The aspiration of South Korean public for the reunification and democracy of Korea pushed policy makers over despotic rule and the aggressive policy toward North Korea.