The National Security Policy Directives (NSPD) was previously known as Presidential Policy Directives (PDD); the renaming occurred during the initial days of President George W. Bush's first term in office (Aftergood, 2010). The NSPD consists of dictums on national security matters as decided upon by the president; their main aim being the promulgation of the directives (Aftergood, 2010). The directives are divided into numbered sections with each section containing self-explanatory policy directives with topics ranging from national to international matters, but all having a direct association with state security and deriving authority from the central government.
The NSPD directives act as reliable references for many researchers conducting studies on issues relating to national security, for instance Summers (2008) used the directive NSPD 51 when he conducted a study to explain United States Africa Command's (AFRICOM) policy to the rest of the world at a time when the United States of America was getting a lot of international criticism for creating a separate military unified command for Africa, Summers (2008) stated;
According to the National Security Policy Directive (NSPD) 51, US Strategy for sub-Saharan Africa, the military's role emphasizes three objectives: 1) civilian control of the military and defense reform, 2) military professionalism, and 3) security capacity building (p. 3)And went on to illustrate that the purpose for the policy, as rooted on the directive, was specifically meant for peacekeeping operations which is a positive intention.
The National Security Council is the body entitled with the formal checking and approving, for release, of the directives. Currently there are sixty-six directives that have been published, the first of which was published on 13th February 2001, and others being published over the past eight years since as issues necessitated. The diversity of security related issues caused the birth of the Homeland Security Presidential Directives from the NSPD so as differentiate the homeland security policies from those with an international scope.