Congress passed the Nunn-Lugar amendment, authorizing U.S. threat reduction assistance to the former Soviet Union, in November 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 in the DOD budget to over $1 billion per year across three agencies-DOD, DOE, and the State Department. It has also evolved from an emergency response to impending chaos in the Soviet Union, to a more comprehensive threat reduction and nonproliferation effort, to a broader program seeking to keep nuclear, chemical, and biological weapons from leaking out of the former Soviet Union and into the hands of rogue nations or terrorist groups, to a global program to address the threat of weapons of mass destruction.