The President issued an executive order this week listing the order of succession for the position of Secretary of Defense.  This list is periodically updated to reflect the latest legislation or policy changes.  The President has the authority to make this determination under the Constitution and the Federal Vacancies Reform Act of 1998.  The executive order provides for the succession of officials who would perform the functions and duties of Secretary of Defense should the Secretary die, resign, or become unable to perform those functions and duties.  The Deputy Secretary of Defense leads the list, followed in order by the Secretaries of the Army, Navy, and Air Force.  Next are the Under Secretaries of Defense, led by the Under Secretary of Defense for Acquisition, Technology, and Logistics.  The Under Secretary of Defense (Comptroller) is in the seventh position.  Only individuals that are appointed by the President and confirmed by the Senate and are not in an acting capacity can act as Secretary of Defense.