This bachelor thesis focuses on the ethics concerning the possession of nuclear weapons seen from a deontological and utilitarian perspective. I have also considered the aspects of International law, the Just-war Theory, and Michael Walzer's Legalist Paradigm. The research question that guides my essay is: Is it possible to ethically justify a country's possession of nuclear arms, which results in direct and indirect threats against other countries?I have chosen to focus my essay on the period of 1945 to 1990, also referred to as the Cold War. I find the bipolar system that existed between the USA and the Soviet Union as a good empirical example, during which the nuclear arms debate constantly took place.The result that my thesis brings is rather ambiguous.