((a))
((1)) There are six Deputy Under Secretaries of Defense.
((2)) The Deputy Under Secretaries of Defense shall be appointed from civilian life by the President, by and with the advice and consent of the Senate.
((3)) The officials authorized under this section shall be the only Deputy Under Secretaries of Defense.
((b)) Each Deputy Under Secretary of Defense shall be the first assistant to an Under Secretary of Defense and shall assist such Under Secretary in the performance of the duties of the position of such Under Secretary and shall act for, and exercise the powers of, such Under Secretary when such Under Secretary dies, resigns, or is otherwise unable to perform the functions and duties of the office.
((c))
((1)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense for Research and Engineering.
((2)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense for Acquisition and Sustainment.
((3)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense for Policy.
((4)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense for Personnel and Readiness.
((5)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense (Comptroller).
((6)) One of the Deputy Under Secretaries is the Deputy Under Secretary of Defense for Intelligence and Security, who shall be appointed from among persons who have extensive expertise in intelligence matters.
((d)) The Deputy Under Secretaries of Defense take precedence in the Department of Defense after the Secretary of Defense, the Deputy Secretary of Defense, the Secretaries of the military departments, and the Under Secretaries of Defense. The Deputy Under Secretaries shall take precedence among themselves in the order prescribed by the Secretary of Defense.