The U.S. Department of Defense (DOD) is a federal department regulating and monitoring those agencies related to national security as well as the U.S. armed forces. Regulations relating to the DOD are codified in 10 USCS prec § 111. The DOD is divided into three components:
1.The Department of Army,
2.The Department of Navy,
3.The Department of Air Force.
Some of the agencies that come under the DOD are:
1.The Pentagon Force Protection Agency (PFPA),
2. The Defense Intelligence Agency (DIA),
3.The National Geospatial-Intelligence Agency (NGA), and
4. The National Security Agency (NSA).
The DOD is led by the Secretary of Defense. The DOD is authorized to supervise and control military forces of the U.S. and is also responsible for organizing, training and equipping military units. The Secretary of Defense, for the purpose of protecting the U.S. forces, is also authorized to purchase weapons from any foreign person, foreign government, international organization, or other entity located in that country.