ISN fights fire without fire. The Bureau of International Security and Nonproliferation (ISN) is the US point agency in preventing the spread of chemical, nuclear, and biological weapons of mass destruction (WMD). It uses multilateral diplomacy to create international agreement on WMD proliferation, implement international treaties, and support foreign allies in preventing the use of WMD by terrorists. ISN works through about a dozen offices including the Office of Weapons of Mass Destruction Terrorism, the Office of Conventional Arms Threat Reduction, and the Office of Chemical and Biological Weapons Threat Reduction. The bureau is part of the State Department.