Department of Defense

A number of agencies assist the Defense Department. The National Security Agency/Central Security Service performs specialized technical and coordinating functions relating to national security. The Defense Nuclear Agency provides support to all the armed forces in matters related to nuclear weapons, their effects and testing. The Defense Information Systems Agency is responsible for operational and management direction of a worldwide communications system for the armed forces and other government agencies. The Defense Intelligence Agency organizes and directs Defense Department intelligence resources and reviews and coordinates intelligence functions assigned to the military departments. The Defense Logistics Agency provides supply and service support for items common to all services; this includes procurement of matériel, operation of a wholesale distribution system, and surplus-disposal programs. Other supporting agencies are the Defense Contract Audit Agency, Defense Advanced Research Projects Agency, Defense Investigative Service, Defense Mapping Agency, Defense Legal Services Agency, Defense Security Assistance Agency, and the On-Site Inspection Agency.