ABSTRACT
The legality of the threat or use of nuclear weapons was not being assessed when the atomic bomb was developed during the Second World War. Instead, all relevant deliberations had concentrated on how to end that war quickly without considering questions related to the future role of nuclear weaponry. Important rules of international law which inform a professional legal assessment today, including the UN Charter, have entered into force only after the first and so far only case when nuclear weapons were used. Furthermore, the role of nuclear weapons has undergone important changes since the end of superpower confrontation during the Cold War, and so have the challenges posed by their existence. Hence any legal assessment must consider the different historic phases for the role of nuclear weapons in military planning and decision-making. Different branches of international law are relevant in this respect. It is in this broader context that the role of states and non-state actors in the development of pertinent principles and rules are to be considered.
