31. National Security Decision Memorandum 2421


  • Secretary of State
  • Secretary of Defense
  • Director, Central Intelligence Agency
  • Director, Arms Control and Disarmament Agency


  • Policy for Planning the Employment of Nuclear Weapons

Based on a review of the study conducted in response to NSSM 1692 and discussions by the Verification Panel,3 I have reached the following decisions on United States policy regarding planning for nuclear weapons employment. These decisions do not constitute a major [Page 143]new departure in U.S. nuclear strategy; rather, they are an elaboration of existing policy. The decisions reflect both existing political and military realities and my desire for a more flexible nuclear posture.

This NSDM provides the policy framework for planning the employment of U.S. nuclear weapons. It also establishes the process by which the principal aspects of this policy will be coordinated, reviewed and revised.

Planning Nuclear Weapons Employment for Deterrence

The fundamental mission of U.S. nuclear forces is to deter nuclear war, and plans for the employment of U.S. nuclear forces should support this mission. Our deterrence objectives are:

(1) To deter nuclear attacks against the United States, its forces, and its bases overseas.

(2) In conjunction with other U.S. and allied forces, to deter attacks—conventional and nuclear—by nuclear powers against U.S. allies and those other nations whose security is deemed important to U.S. interests.

(3) To inhibit coercion of the United States by nuclear powers and, in conjunction with other U.S. and allied forces, help inhibit coercion of U.S. allies by such powers.

The United States will rely primarily on U.S. and allied conventional forces to deter conventional aggression by both nuclear and non-nuclear powers. Nevertheless, this does not preclude U.S. use of nuclear weapons in response to conventional aggression.

Planning Limited Nuclear Employment Options

Should conflict occur, the most critical employment objective is to seek early war termination, on terms acceptable to the United States and its allies, at the lowest level of conflict feasible. This objective requires planning a wide range of limited nuclear employment op-tions which could be used in conjunction with supporting political and military measures (including conventional forces) to control escalation.

Plans should be developed for limited employment options which enable the United States to conduct selected nuclear operations, in concert with conventional forces, which protect vital U.S. interests and limit enemy capabilities to continue aggression. In addition, these options should enable the United States to communicate to the enemy a determination to resist aggression, coupled with a desire to exercise restraint.

Thus, options should be developed in which the level, scope, and duration of violence is limited in a manner which can be clearly and credibly communicated to the enemy. The options should (a) hold [Page 144]some vital enemy targets hostage to subsequent destruction by survivable nuclear forces, and (b) permit control over the timing and pace of attack execution, in order to provide the enemy opportunities to reconsider his actions.

Planning for General War

In the event that escalation cannot be controlled, the objective for employment of nuclear forces is to obtain the best possible outcome for the United States and its allies. To achieve this objective, employment plans should be developed which provide to the degree practicable with available forces for the following:

(1) Maintenance of survivable strategic forces in reserve for protection and coercion during and after major nuclear conflict.

(2) Destruction of the political, economic, and military resources critical to the enemy’s postwar power, influence, and ability to recover at an early time as a major power.

(3) Limitation of damage to those political, economic, and military resources critical to the continued power and influence of the United States and its allies.

Further Guidance and Presidential Review of Employment Plans

The Secretary of Defense shall issue guidance4 consistent with this NSDM to serve as the basis for the revision of operational plans for the employment of nuclear forces by the Joint Chiefs of Staff. An information copy of this guidance should be provided to the President and Secretary of State.

Within three months, the Secretary of Defense shall present for Presidential review an initial set of limited employment options. At quarterly intervals thereafter, the Secretary of Defense shall present for Presidential review a summary of available options and an analysis of any additional recommended options. Each presentation should include illustrative scenarios for each limited employment option.

Within six months the Secretary of Defense shall submit to the President an analysis of the political, economic, and selected military targets considered critical to potential enemy’s post war power influence and recovery as a major power. Appropriate aspects of this analysis should be coordinated with the Secretary of State and the Director of Central Intelligence.

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In addition, the Secretary of Defense shall submit to the President an evaluation of the effectiveness, limitations and risks of the resultant operational plans. Interim results of this evaluation should be reported approximately every six months at significant points in the process of revision.

Command, Control, and Crisis Management

To insure that nuclear forces are responsive to the national command authorities, employment planning for command, control, communications and surveillance must support decision-making and force execution, taking into account U.S. nuclear employment objectives and options, the survivability of the forces themselves, and the consequences of direct attack on the command control systems. At a minimum, this planning should provide for:

(1) Essential support to decision-making and execution of retaliatory strikes in the event of large attacks on the United States.

(2) Adequate support for decision-making and flexible use of nuclear forces in attempts to control escalation in local conflict. Employment planning for this function may assume that the national level command, control, and communications systems and associated sensors supporting the National Command Authorities are not subject to direct attack.

With regard to crisis management procedures:

(1) The Secretary of State, Secretary of Defense, and the Director of Central Intelligence shall refine their crisis management procedures to provide timely political-military assessments and recommendations to the National Command Authority to support potential nuclear employment decisions. The revised procedures should be submitted to the President for review by March 31, 1974.

(2) The Secretary of Defense shall in addition submit to the President by March 31, 1974, detailed recommendations on the desirability, composition, operations, facilities, and physical location of a senior level staff to provide prompt military advice to the National Command Authority on the possible use of nuclear forces in a crisis.

(3) The Assistant to the President for National Security Affairs, in consultation with the Secretaries of State and Defense and the Director of Central Intelligence, shall conduct a continuing evaluation of the national level crisis management procedures. Within six months, the Defense Program Review Committee shall prepare an initial report on the adequacy of present interagency organizational arrangements for Presidential review. Future annual reports shall contain evaluations of appropriate tests and exercises of these procedures.

Additional Actions

The Secretary of State shall prepare an analysis of any necessary actions related to informing the NATO Alliance and other states, in[Page 146]cluding the Soviet Union and the PRC, of changes in U.S. nuclear policy.5 The analysis should include a discussion of the extent to which we need to inform other states and the key considerations in making decisions on these issues. This study should identify for each alliance and, as applicable, on a nation-by-nation basis, those aspects whose disclosures should be avoided. In support of this effort, the Director of Central Intelligence should prepare a special assessment of likely Soviet and PRC reactions to the new policies, and how these might be influenced by US statements and actions.

The Secretary of Defense should prepare an analysis, from the point of view of military preparedness, of the desirability of any changes in current arrangements for allied participation in NATO nuclear planning.

The results of these additional actions should be submitted for review by the Verification Panel by March 31, 1974.

Richard Nixon
  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 364, Subject Files, NSDMs 145–264. Top Secret; Sensitive. Copies were sent to Ray and Moorer.
  2. See Document 17.
  3. See Document 22.
  4. Under an April 10 covering memoranda, Wickham forwarded to Scowcroft the OSD’s “Policy Guidance for the Employment of Nuclear Weapons,” which set forth strategic concepts, planning concepts, major and selected attack options, and limited and regional nuclear options. (Ibid., NSC Institutional Files (H-Files), Box H–243, Policy Papers, NSDM 242, 1 of 2 [2 of 2])
  5. Under a May 10 covering memorandum, Rush distributed the Department’s report on declaratory policy, which noted that foreign reactions to the new U.S. nuclear employment policy had been “varied.” Whereas, Japan and the PRC had responded with “near silence,” Western European “reactions have been largely favorable, reflecting the view that the strengthening of the US military capability would enhance their own security.” Meanwhile, Soviet reactions were “negative,” reflecting “concern that the new doctrine is inconsistent” with SALT. (Ibid., RG 59, S/S–I Files, Lot File 83D305, NSDMs, 1969–1977, NSDM 242)