Nuclear weapons are tools of mass destruction that have sparked much debate about their impact on global security. Since it was first used in 1945, the consequences of its use have changed dramatically. The influence of these weapons is not only visible in armed conflicts, but also in the foreign policies of countries that have and do not have these weapons. First, nuclear weapons create a balance of fear among states. The doctrine of deterrence underlies the defense strategies of many nuclear-armed states, where the assumption is that a nuclear attack will be responded to with a similar counterattack. This creates strategic stability but also increases the risk of miscalculations, which could lead to nuclear war. Second, nuclear proliferation is a serious problem in global security. Countries such as North Korea and Iran show that nuclear technology is accessible to regional countries that do not even have large military powers. This increases tensions in certain regions and threatens existing stability. Third, nuclear weapons also have an impact on international diplomatic policy. Treaties such as the Non-Proliferation Treaty (NPT) and various regional security instruments seek to limit the spread of nuclear weapons. However, countries with nuclear powers often experience different pressures compared to non-nuclear countries, creating inequities in the global security system. Fourth, the environmental impact of nuclear weapons produces far wider consequences. Nuclear explosions can cause prolonged radiation, damage ecosystems, and create nuclear waste that is difficult to deal with. This issue not only depends on the country that has the weapons, but also affects the country wherever the explosion occurs. Furthermore, the psychological impact of nuclear weapons on society cannot be doubted. Fear of nuclear attack can create social and political uncertainty, and increase challenges for governments in maintaining domestic stability. A threatened sense of security often leads to increased military spending, ignoring other social issues. Lastly, nuclear weapons influence the development of military technology as a whole. Countries sought to maintain superiority in technology to protect themselves from nuclear threats, fueling a conventional and unconventional arms race. This creates a vicious circle in which spending on nuclear weapons diverts funds from economic and social development. The existence of nuclear weapons in the modern world is a real challenge that requires international cooperation. Effective diplomacy and a commitment to reducing nuclear arsenals are essential to creating a safer and more stable environment for all countries. Nuclear weapons are not only a threat to the countries they target, but also to global security as a whole.