10 U.S.C. § 133b

(a) Under Secretary of Defense .— There is an Under Secretary of Defense for Acquisition and Sustainment, appointed from civilian life by the President, by and with the advice and consent of the Senate. The Under Secretary shall be appointed from among persons who have an extensive system development, engineering, production, or management background and experience with managing complex programs. A person may not be appointed as Under Secretary within seven years after relief from active duty as a commissioned officer of a regular component of an armed force. (b) Duties and Powers .— Subject to the authority, direction, and control of the Secretary of Defense, the Under Secretary shall perform such duties and exercise such powers as the Secretary may prescribe, including— (1) serving as the chief acquisition and sustainment officer of the Department of Defense with the mission of delivers end-user capabilities with speed and innovation to counter threats and cost-effectively sustain the military advantage of the United States; (2) establishing policies on, and supervising, all elements of the Department relating to acquisition (including system design, development, appropriate prototyping activities, and production, and procurement of goods and services) and sustainment (including logistics, maintenance, and materiel readiness); (3) establishing policies for access to, and maintenance of, the defense industrial base and materials critical to national security, and policies on contract administration; (4) establishing policies for, and providing oversight, guidance, and coordination with respect to, the nuclear command, control, and communications system; (5) serving as— (A) the principal advisor to the Secretary on acquisition and sustainment in the Department; (B) the senior procurement executive for the Department for the purposes of section 1702(c) of title 41 ; (C) the Defense Acquisition Executive for purposes of regulations and procedures of the Department providing for a Defense Acquisition Executive; (D) chairman of the Nuclear Weapons Council established by section 179 of this title ; and (E) co-chairman of the Council on Oversight of the National Leadership Command, Control, and Communications System established by section 171a of this title ; (6) overseeing— (A) the sustainment and modernization of United States nuclear forces, including the nuclear command, control, and communications system; and (B) military department and Defense Agency programs to develop defenses against chemical and biological weapons and capabilities to counter weapons of mass destruction; (7) the authority to direct the Secretaries of the military departments and the heads of all other elements of the Department with regard to matters for which the Under Secretary has responsibility, except that the Under Secretary shall exercise advisory authority over service acquisition programs for which the service acquisition executive is the milestone decision authority; (8) to the extent directed by the Secretary, exercising overall supervision of all personnel (civilian and military) in the Office of the Secretary of Defense with regard to matters for which the Under Secretary has responsibility, unless otherwise provided by law; (9) advising the Secretary on all aspects of acquisition and sustainment relating to— (A) the defense acquisition system, in accordance with the objectives established pursuant to section 3102 of this title ; (B) core logistics capabilities (as described under section 2464 of this title ); and (C) the national technology and industrial base (as defined in section 4801 of this title ); and (10) advising the Secretary on, establishing policies on, and supervising, the activities of the Department relating to international cooperation and agreements regarding industrial base collaboration and coordination, including cooperative development and co-production, reciprocal production, exportability considerations, supply chain integration, security of supply chain agreements, and acquisition and cross-service agreements. (c) Precedence in Department of Defense.— (1) Precedence in matters of responsibility .— With regard to all matters for which the Under Secretary has responsibility by the direction of the Secretary of Defense or by law, the Under Secretary takes precedence in the Department of Defense after the Secretary, the Deputy Secretary of Defense, and the Under Secretary of Defense for Research and Engineering. (2) Precedence in other matters .— With regard to all matters other than the matters for which the Under Secretary has responsibility by the direction of the Secretary or by law, the Under Secretary takes precedence in the Department of Defense after the Secretary, the Deputy Secretary, the Under Secretary of Defense for Research and Engineering, and the Secretaries of the military departments.