http://www.whitehouse.gov/sites/default/files/docs/2015_national_security_strategy_2.pdf
Updates the strategy document released five years ago. Cites the leading threats as attacks on the homeland or on American citizens abroad, global economic crisis, proliferation of weapons of mass destruction, infectious disease outbreaks, and climate change. From the White House
http://fas.org/irp/eprint/attribution.pdf
Recently declassified 2009 report on the challenge of identifying the perpetrator of a potential nuclear attack on the U.S. and the problems in reconciling the careful search for and analysis of forensic evidence with the demand for speed from the policy/political environment. From the Office of the Director of National Intelligence, posted by the Federation of American Scientists.
Seeks to ensure that the U.S. and its allies are neither attacked nor coerced by actors with WMD. The strategy also establishes countering objectives, defines an approach for achieving them, and identifies essential activities. From the Department of Defense
http://www2.gwu.edu/~nsarchiv/nukevault/ebb480/
A collection of 12 formerly classified documents dating from the late 1950s and early 1960s which reveal estimates of potential damage from a nuclear exchange with the Soviet Union. The documents are mostly summaries from the still-classified full-length reports from the National Security Council’s highly secret Net Evaluation Subcommittee. From the National Security Archive
http://www.fas.org/sgp/crs/nuke/R43143.pdf
This report summarizes cooperative activities conducted during the full 20 years of U.S. threat reduction and nonproliferation assistance. Reviews the programs and their funding. From the Congressional Research Service, posted by the Federation of American Scientists
http://www.state.gov/documents/organization/225045.pdf
Annual report on trends and events in international terrorism including country reports on counterterrorism efforts, terrorist safe havens, terrorist organizations, and the challenge of chemical, biological, radiological, and nuclear terrorism. From the State Department
http://www.fas.org/sgp/crs/nuke/R43480.pdf
Describes the key elements of a nuclear weapons program, reviews the available information regarding cooperation among Iran, North Korea, and Syria on ballistic missiles and nuclear technology, and discusses additional requirements that Congress may wish to impose, especially with regard to executive branch reporting on WMD proliferation. From the Congressional Research Service, posted by the Federation of American Scientists
http://www.state.gov/j/ct/rls/other/rpt/221544.htm
Describes U.S. government spending on programs of assistance and training related to countering terrorism. The spending covers agencies other than the Department of Defense. From the State Department