(a) Review Required. - The Secretary of Defense shall every four years, during a year following a year evenly divisible by four, conduct a comprehensive examination (to be known as a "quadrennial defense review") of the national defense strategy, force structure, force modernization plans, infrastructure, budget plan, and other elements of the defense program and policies of the United States with a view toward determining and expressing the defense strategy of the United States and establishing a defense program for the next 20 years.

Each such quadrennial defense review shall be conducted in consultation with the Chairman of the Joint Chiefs of Staff. (b) Conduct of Review. - Each quadrennial defense review shall be conducted so as - (1) to delineate a national defense strategy consistent with the most recent National Security Strategy prescribed by the President pursuant to section 108 of the National Security Act of 1947 (50 U.S.C. 404a); (2) to define sufficient force structure, force modernization plans, infrastructure, budget plan, and other elements of the defense program of the United States associated with that national defense strategy that would be required to execute successfully the full range of missions called for in that national defense strategy; and (3) to identify (A) the budget plan that would be required to provide sufficient resources to execute successfully the full range of missions called for in that national defense strategy at a low-to-moderate level of risk, and (B) any additional resources (beyond those programmed in the current future-years defense program) required to achieve such a level of risk. (c) Assessment of Risk. - The assessment of risk for the purposes of subsection (b) shall be undertaken by the Secretary of Defense in consultation with the Chairman of the Joint Chiefs of Staff.

That assessment shall define the nature and magnitude of the political, strategic, and military risks associated with executing the missions called for under the national defense strategy. (d) Submission of QDR to Congressional Committees. - The Secretary shall submit a report on each quadrennial defense review to the Committees on Armed Services of the Senate and the House of Representatives.

The report shall be submitted in the year following the year in which the review is conducted, but not later than the date on which the President submits the budget for the next fiscal year to Congress under section 1105(a) of title 31. The report shall include the following: (1) The results of the review, including a comprehensive discussion of the national defense strategy of the United States and the force structure best suited to implement that strategy at a low-to-moderate level of risk. (2) The assumed or defined national security interests of the United States that inform the national defense strategy defined in the review. (3) The threats to the assumed or defined national security interests of the United States that were examined for the purposes of the review and the scenarios developed in the examination of those threats. (4) The assumptions used in the review, including assumptions relating to - (A) the status of readiness of United States forces; (B) the cooperation of allies, mission-sharing and additional benefits to and burdens on United States forces resulting from coalition operations; (C) warning times; (D) levels of engagement in operations other than war and smaller-scale contingencies and withdrawal from such operations and contingencies; and (E) the intensity, duration, and military and political end-states of conflicts and smaller-scale contingencies. (5) The effect on the force structure and on readiness for high-intensity combat of preparations for and participation in operations other than war and smaller-scale contingencies. (6) The manpower and sustainment policies required under the national defense strategy to support engagement in conflicts lasting longer than 120 days. (7) The anticipated roles and missions of the reserve components in the national defense strategy and the strength, capabilities, and equipment necessary to assure that the reserve components can capably discharge those roles and missions. (8) The appropriate ratio of combat forces to support forces (commonly referred to as the "tooth-to-tail" ratio) under the national defense strategy, including, in particular, the appropriate number and size of headquarters units and Defense Agencies for that purpose. (9) The strategic and tactical air-lift, sea-lift, and ground transportation capabilities required to support the national defense strategy. (10) The forward presence, pre-positioning, and other anticipatory deployments necessary under the national defense strategy for conflict deterrence and adequate military response to anticipated conflicts. (11) The extent to which resources must be shifted among two or more theaters under the national defense strategy in the event of conflict in such theaters. (12) The advisability of revisions to the Unified Command Plan as a result of the national defense strategy. (13) The effect on force structure of the use by the armed forces of technologies anticipated to be available for the ensuing 20 years. (14) The national defense mission of the Coast Guard. (15) Any other matter the Secretary considers appropriate. (e) CJCS Review. - (1) Upon the completion of each review under subsection (a), the Chairman of the Joint Chiefs of Staff shall prepare and submit to the Secretary of Defense the Chairman's assessment of the review, including the Chairman's assessment of risk. (2) The Chairman shall include as part of that assessment the Chairman's assessment of the assignment of functions (or roles and missions) to the armed forces, together with any recommendations for changes in assignment that the Chairman considers necessary to achieve maximum efficiency of the armed forces.

In preparing the assessment under this paragraph, the Chairman shall consider (among other matters) the following: (A) Unnecessary duplication of effort among the armed forces. (B) Changes in technology that can be applied effectively to warfare. (3) The Chairman's assessment shall be submitted to the Secretary in time for the inclusion of the assessment in the report.

The Secretary shall include the Chairman's assessment, together with the Secretary's comments, in the report in its entirety.