sentences:  This program seeks to improve the security of nuclear weapons and nuclear weapons material through upgrades to material protection and material control and accounting at nuclear sites in Russia and other countries of the former Soviet Union.Since the program's inception as part of the Department of Defense's Cooperative Threat Reduction Program, it has improved the security on thousands of tons of weapons grade nuclear material in the FSU.The Issue
  
   After the Cold War, there were large quantities of enriched uranium and plutonium-239 left in Russia.