This study suggests theoretical approaches that give a supplement explanation about the application of deterrence theory to the Korean Peninsula situation. The tra-ditional deterrence theory focuses on preventing the escalation of nuclear war by preventing nuclear use before a war. However, there has been insufficient discussions on the risk of nuclear use during a war. Countries with small- and medium-sized nu-clear power are emerging, and nuclear power is proliferating. It calls for a doctrinal shift suitable for achieving limited goals through nuclear use during a war. In this study, we compare the traditional deterrence theory with the intra-war deterrence theory and present the possibility of limited war on the Korean Peninsula.