Congress passed the Nunn-Lugar amendment, authorizing U.S. threat reduction assistance to the former Soviet Union, in Nov. 1991, after a failed coup in Moscow and the disintegration of the Soviet Union raised concerns about the safety and security of Soviet nuclear weapons. The annual program has grown from $400 million to over $1 billion/year across 3 agencies. It has also evolved from an emergency response to impending chaos in the Soviet Union, to a more comprehensive threat reduction and non-proliferation effort, to a broader program seeking to keep nuclear, chemical, and biological weapons from leaking into the hands of rogue nations or terrorists. This report discusses issues related to U.S. non-proliferation and threat reduction assistance. Illus.