Cooperative threat reduction programs were born at the end of the Cold War, when it became apparent that thousands of nuclear weapons might break loose from effective command and control due to the Soviet Union's collapse. Since 1991, the United States has spent more than $12 billion to help secure and destroy nuclear warheads in the former Soviet republics. Throughout their lives, these programs have been controversial, with proponents claiming they offer unique capabilities while critics cite wasted funds and slow progress. As more and more states undertake nuclear programs, threat reduction programs could become increasingly important--if cooperation with Russia is beneficial to US national security, cooperation with other states might also. Thus, an evaluation of cooperative threat reduction is timely and relevant. The research shows that despite some problems, cooperative threat reduction programs are a useful tool in the nation's security kit. They have been effective in eliminating nuclear weapons and securing nuclear materials, though they have led to instances of significant waste and are subject to differing views and political manipulation. Even in the right international context, expanding these programs to additional partner states or technical areas will require significant time and effort to achieve useful results.