In this thesis the Democratic People s Republic of Korea (DPRK) is used as a case to explain the role credible deterrence plays in the 21st century. The goal is to contribute to our understanding of the complex dynamics relating to nuclear weapons between the DPRK, the United States and the Republic of Korea (ROK). It also sheds light on factors that may increase or decrease North Korean deterrence credibility. The main objective is to understand DPRK s nuclear weapons program and explain North Korean deterrence credibility. This thesis does this by drawing upon literature and information provided by respondents through conducted elite interviews. The study uses the information provided to discuss to what extent DPRK s nuclear weapons deter the United States and the ROK. The analysis goes deeper into the relationship between the three states and their nuclear weapons. The aim is to describe the role of deterrence and explain its impact on the relationship between the DPRK, the United States and the ROK. It identifies North Korean nuclear abilities and its will to use nuclear weapons against another state, and it discusses to which degree the United States and the ROK feel threatened by North Korean nuclear weapons. The findings indicate that the United States and the ROK is partially disposed to DPRK s nuclear deterrence because the DPRK do not at this moment have a reliable capability to hit the continental United States with nuclear weapons, but the DPRK has the capability to hit targets in the ROK, and American vital interests outside of the United States. Even though the DPRK can hurt the United States and the ROK with nuclear weapons, it seems unlikely that the DPRK would use nuclear weapons against another state because it appears that the leadership is a rational actor and regime survival is of greatest importance. The thesis argues that the DPRK is unlike any other country, and this makes predicting what the DPRK will do in a given situation almost impossible.