With the collapse of the Soviet Union in 1991, Russia inherited the world’s largest arsenal of weapons of mass destruction (WMD). Since 1993, the United States has undertaken efforts to reduce the threat and proliferation of WMD in Russia through the authorization of congressional funds for programs to help destroy Russian weapons and improve WMD security. This report presents overall observations on the progress and key challenges of these programs. The United States has provided $6.4 billion for the Departments of Defense, Energy, and State programs in the former Soviet Union. Progress has been identified in three areas: (1) the Department of Defense has aided in destroying 463 Russian nuclear submarines, long-range bombers, and strategic missiles; (2) the Department of Energy installed security systems that helped protect 32 percent of Russia’s weapons-usable nuclear material; and (3) the United States supplemented the income of thousands of Russian weapons scientists to reduce their inclination to sell their skills to other countries. However, the United States continues to face to two significant challenges: (1) the Russian Government has not always paid its agreed-upon share of program costs and (2) Russian ministries often deny U.S. officials access to key nuclear and biological sites. The United States now employs alternatives to onsite access through the use of photographs and videotapes before and after the installation of security systems, visual inspections, and written certification by Russian site directors.