International Nuclear Security Law: The Use of 'Soft Law'.

This article provides an overview of international nuclear security law, focusing on the interplay between legally binding treaties—such as the Convention on the Physical Protection of Nuclear Material (CPPNM) and its amendment (A/CPPNM)—and non-legally binding "soft law" instruments like the International Atomic Energy Agency's (IAEA) Nuclear Security Series (NSS). It explains that while soft law lacks formal legal binding force internationally, it is often transposed into municipal law, thereby gaining mandatory status at the national level to accommodate the diverse nuclear facility environments across IAEA Member States. The article also discusses the role of bilateral and regional agreements, transportation regulations by organizations such as the International Civil Aviation Organization (ICAO) and the International Maritime Organization (IMO), and the importance of soft law in addressing extraordinary circumstances, including armed conflict and natural disasters. Ultimately, it highlights how the complementary use of hard law and soft law, supported by international cooperation and advisory services like the IAEA's International Physical Protection Advisory Service (IPPAS), enables flexible yet robust nuclear security governance worldwide.