Convention on the Physical Protection of Nuclear Material
The Convention on the Physical Protection of Nuclear Material (CPPNM) is a legally binding international treaty relating to the prevention, detection, and punishment of offenses related to nuclear material. The Convention requires that state parties take appropriate steps to ensure that during international transport, nuclear material under their control is protected at levels reflective of the categorization of material being transported (i.e. Category I, II, etc.).

Amendment to the Convention on the Physical Protection of Nuclear Material
The Amendment to the Convention on the Physical Protection of Nuclear Material (A-CPPNM) expands the scope of original Convention to include domestic nuclear facilities and materials, as well as storage and transport security. The Amendment also facilitates increased cooperation between and among states in the detection and prosecution of offenses relating to the theft or smuggling of nuclear material.

International Convention on the Suppression of Acts of Nuclear Terrorism
The International Convention on the Suppression of Acts of Nuclear Terrorism (commonly known as the Nuclear Terrorism Convention) is an international treaty which outlines offences relating to the unlawful possession and use of radioactive substances with the intent to cause death or serious bodily injury, or with the intent to cause property damage or damage to the environment. The Convention encourages states to adopt measures, including domestic legislation, to ensure that such offences do not occur and, when they do, that they are punished with penalties consistent with the gravity of the offense. The Convention also promotes increased cooperation and assistance between states in the investigation and prosecution of such crimes.

United Nations Security Council Resolution 1373
United Nations Security Council Resolution 1373 was passed unanimously in the immediate aftermath of the September 11th terrorist attacks. It urges states to cooperate on combating international terrorism, and obliges all states to criminalize assistance to terrorists and terrorist activities. It specifically expresses concern over the connection between international terrorism and the illegal movement of nuclear materials, and urges increased national, regional, and international collaboration on battling this threat. 

United Nations Security Council Resolution 1540
United Nations Security Council Resolution 1540 is a UN resolution passed in 2004 which affirms that the proliferation of weapons of mass destruction (WMD) and their means of delivery constitutes a threat to international security and requires that states refrain from providing material or informational support to actors seeking to develop, acquire, manufacture, posses, transfer, or use WMD. The Resolution requires states to establish domestic controls and instruments to prevent the illicit trafficking of materials which could be used in a terrorist attack.

United Nations Security Council Resolution 1887
United Nations Security Council Resolution 1887 is a binding UN resolution passed in 2009 relating to nuclear non-proliferation and disarmament. The resolution calls on states to the Nuclear Non-Proliferation Treaty (NPT) to comply with their obligations and commitments under the treaty; calls for a treaty banning the production of fissile material for nuclear weapons; calls for adherence and implementation of UNSCR 1540, CPPNM, as well as the Nuclear Terrorism Convention; calls on member states to share best practices in order to improve nuclear safety and security standards; and calls on states to enhance their capabilities in the detection, determent, and disruption of illicit trafficking in radioactive materials.

Global Initiative to Combat Nuclear Terrorism
This document outlines the statement of principles that the 85 members of the Global Initiative to Combat Nuclear Terrorism ascribe to. These principles reflect a commitment on behalf of member states to undertake the necessary steps to improve the accounting and protection of weapons-usable material; develop and enhance their interdiction capabilities; prevent non-state actors from gaining possession of sensitive materials; establish laws and regulations to counter such persons/organizations; and to develop response and mitigation capabilities for acts of nuclear terrorism.

Proliferation Security Initiative
The Proliferation Security Initiative (PSI) is a U.S.-sponsored global initiative aimed at limiting the trafficking of weapons of mass destruction and related materials to and from states and non-state actors.  Parties to the PSI commit, to the extent of their capabilities and legal powers, to the interdiction of transfers of WMD and related materials and to strengthen the relevant authorities tasked with doing so. The PSI also encourages the development of procedures for information exchange between countries.