The United States faces a small number of rogue states that either have or are working to acquire weapons of mass destruction. These NASTIs, or NBC-Arming Sponsors of Terrorism and Intervention, include such states as North Korea, Iraq, Iran, Libya, and Syria. U.S. nonproliferation programs and policies have helped to keep this number small, but U.S. and allied counterproliferation programs are essential to reduce the danger. It is up to deterrence,...