The end of the Cold War has brought both uncertainty and opportunity for states interested in designing their own security policies. Alternative methods, other than military solutions, should be exploited to prevent insecurity and instability. This study is concerned with South Korea's security approach towards North Korea in the post-Cold War era and in particular how South Korea can use non-military tools to prevent military conflict in the Korean Peninsula and to build mutual confidence between the two Koreas in the long-run. This thesis also presents an analysis of both the need and the opportunity for South Korea to adopt a comprehensive economic engagement strategy towards North Korea in the post-Cold War era in order to achieve these goals. It argues that South Korea's implementation of economic engagement with North Korea requires its policy-makers' strong policy-making will for an active and consistent engagement posture. Then, this study demonstrates the important role of President Kim Dae-jung's strong causal beliefs about the necessity of engagement measures to address the post-Cold War North Korean security problems on the Kim Dae-jung government's policy-making in favour of comprehensive engagement with North Korea. This study presents the model of 'business-track diplomacy' to test a state's utilisation of economic engagement strategy as security policy. This model provides ways to think around security issues and alternative security options which go beyond the traditional military containment approach to security in international relations (IR). Moreover, this study presents a new belief perspective that illuminates the South Korea's North Korea policy-making process, which had previously been dominated by military issues and essentially required an international structure perspective, centred on US influence. Thus, the belief approach contributes to the field of foreign policy analysis (FPA) for South Korea by proving the importance of its decision-makers' policy beliefs and by going beyond the conventional international structure approach.