[en] The responsibility for nuclear security rests entirely with each State. There is no single international instrument that addresses nuclear security in a comprehensive manner. The legal foundation for nuclear security comprises international instruments and recognized principles that are implemented by national authorities. Security systems at the national level will contribute to a strengthened and more universal system of nuclear security at the international level. The binding security treaties are; Convention on the Physical Protection of Nuclear Material, the 2005 amendment thereto, Safeguards Agreements between the Agency and states required in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons. Model Protocol additional to agreement(s) between State(s) and the Agency for the application of Safeguards Convention on Early Notification of a Nuclear Accident, Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, Convention on Nuclear Safety, Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management