Weapons of mass destruction (WMD), especially in the hands of radical states and terrorists, represent a major threat to U.S. national security interests. Multilateral regimes were established to restrict trade in nuclear, chemical, and biological weapons and missile technologies, and to monitor their civil applications. Congress may consider the efficacy of these regimes in considering the potential renewal of the Export Administration Act, as well as other proliferation specific legislation in the 111th Congress. This report provides background and current status information on the regimes.