The Cooperative Threat Reduction (CTR) Program (occasionally known as Nunn–Lugar based on a 1992 U.S. law sponsored by Senators Sam Nunn and Richard Lugar) is an initiative housed within the Defense Threat Reduction Agency (DTRA). According to the CTR website, "the purpose of the CTR Program is to secure and dismantle weapons of mass destruction and their associated infrastructure in former Soviet Union states."
CTR provides funding and expertise for states in the former Soviet Union (including Russia, Ukraine, Georgia, Azerbaijan, Belarus, Uzbekistan, and Kazakhstan) to decommission nuclear, biological, and chemical weapon stockpiles, as agreed by the Soviet Union under disarmament treaties such as SALT II. Under the scrutiny of American contractors, nuclear warheads would be removed from their delivery vehicles, then decommissioned or stockpiled at designated sites in Russia.
In recent years, the CTR program has expanded its mission from WMD at the root source to protecting against WMD "on the move" by enhancing land and maritime border security in the Former Soviet Union.