The international community does not permit nuclear-developing and nuclear-weapon states to develop nuclear weapons any more. Some countries (Libya, Ukraine, Iraq, and South Africa) have given up their nuclear weapons or declared an international agreement due to their efforts, while others (North Korea, Iran) have failed in denuclearization despite economic sanctions pressures.
The main purpose of this thesis is to examine the factors that determine the success or failure of denuclearization through the denuclearization process of Libya, Ukraine, Iraq, South Africa, Iran, and North Korea. Economic sanctions and domestic pressure and control on North Korea and Iran acted as a factor in maintaining the regime rather than giving up its nuclear weapons. The failure of North Korea and Iran to achieve denuclearization despite continuous economic sanctions and return to the point of failure can be found in structural factors. As an international factor among structural constraint factors, although there is a difference in influence, both Iran and North Korea have supported countries, and their existence still has a great influence on the development of nuclear weapons. And one of the domestic factors is internal cohesion. The shared belief of the religious coherence of North Korea's Juche ideology and Iran's Islam can be seen as a decisive factor in the failure of denuclearization. Furthermore, considering that one of the common points of the successful denuclearization cases is that they voluntarily dismantled their nuclear weapons, the international community is not only able to choose denuclearization by itself, rather than external sanctions and pressure, but also to North Korea and Iran, which have strong internal solidarity.