Nobuo Hayashi is Visiting Lecturer at the United Nations Interregional Crime and Justice Research Institute. He has two decades of experience researching, publishing, and teaching, including practice at court where he authored submissions, advised prosecutors, and delivered expert presentations at academic and diplomatic conferences. Dr Hayashi specialises in the law of armed conflict, international criminal law and public international law. His most significant works cover military necessity, threat of force, and the law and ethics of nuclear weapons.