171. National Security Decision Memorandum 1171


  • The Members of the National Security Council
  • The Attorney General
  • The Director, Arms Control and Disarmament Agency
  • The Director of Central Intelligence


  • Instructions for Strategic Arms Limitation Talks at Helsinki (SALT V)

Having considered the discussion and recommendations of the National Security Council,2 I have decided on the United States position for presentation at Helsinki (SALT V),3 as detailed in the attached statement.

The Delegation should prepare a draft agreement incorporating the provisions of the United States position in appropriate language. This agreement should be returned to the White House for review and approval prior to presentation at Helsinki. It is intended that the Delegation table a single document, containing all elements of the U.S. position, as early as possible in the Helsinki round. The final form (e.g., treaty) of the agreement will be determined at a later date.

Pending approval and tabling of this draft agreement, the Delegation may outline to the USSR its principal provisions at the beginning of negotiations.

The negotiations on offensive systems and defensive systems must be conducted in parallel. However, at the discretion of the Chairman of the Delegation, there may be an initial period of two to three weeks when the negotiations concentrate on defensive systems. Thereafter, offensive systems must be considered equally and in parallel with defensive systems. Agreements on offensive and defensive systems must be concluded simultaneously.

The Delegation should continue to negotiate an agreed text on Measures to Prevent Accidental War and indicate to the Soviet Delegation [Page 542]that we would prefer that this agreement be concluded simultaneously with agreements on the main areas of limitation (e.g., ABM and offensive measures). Similarly, the Delegation should complete all preliminary work on the Washington–Moscow direct communications link with a view towards concluding this agreement simultaneously with the main agreement.

We can consider separate agreements on Accidents and the communications link; the decision to do so, however, will be taken in light of the general trend of negotiations in Helsinki.

Previous directives concerning the privacy of the talks and public comment on them are reaffirmed.

Richard Nixon



(all provisions apply equally to each side, except as otherwise specifically provided)

Part I

Strategic Offensive Systems

A. Limitations


ICBM launchers and sea-based ballistic missile (SBBM) launchers would be limited to those operational and under active construction as of [the date of the first formal presentation of the U.S. position.]4 (“Active” construction is defined so as not to include the 17 SS–9s on which construction has been started and then abandoned.)

The freeze would include all ICBM launchers and SBBM launchers as defined in paragraphs I.A 4 and 5. Missile launchers for research, development, testing, training, and space missions are covered by a separate limit (under paragraph I.B 1.)

Each side would declare the number of missile launchers operational and under active construction as of the above date.

[It should be made clear to the Soviets that if SLBMs are not included, we would consider it to be granting unilateral advantage to allow completion of the new-type silos now under construction, since a [Page 543]sizeable numerical advantage is already granted in operational ICBM launchers.]

There would be no increase in the number of launchers fitted with modern, large ballistic missiles (MLBMs), (i.e., larger than 70 m3 of any type which first became operational in 1974 or later), beyond the number completed by December 31, 1971. (This is intended to include the 12 SS–9 launchers now under active construction for a total of 288, since external construction is expected to be completed by about this date. It is not meant to include the new-type silos at the operational SS–9 fields.)

Modification of ICBM launchers is permitted, provided that there is no increase in the depth or interior diameter of ICBM launchers, except for those which have been fitted with MLBMs.

[Discussion of the questions of silo relocation, replacement of old SLBM launchers with new ones, and freedom-to-mix from ICBMs to SLBMs should be avoided as being inconsistent with the concept of a freeze. Should the Soviets press the point, the matter should be referred to Washington.]

ICBMs are defined as land-based ballistic missiles which have a capability of ranges in excess of 5,000 kilometers. ICBM launchers, even if deployed for use against targets within MR/IRBM range, would be counted as ICBMs. Launchers for fractional orbital bombardment missile systems (FOBS) would also be counted as ICBMs.
“Sea-based ballistic missiles” are defined as ballistic missiles with launchers on submarines or surface ships, regardless of the nature of the propulsion plant of the vessel, including those of vessels undergoing overhaul or conversion. [If pressed for a definition in terms of range, we would suggest 100 km initially. In any event, tactical systems such as SUBROC would be excluded while the SS–N–4 and 5 would be counted.]

B. Research and Development, Testing, Evaluation, Training and Space Launchers

Missile launchers for research, development, testing, evaluation and training with respect to all strategic offensive missile systems, and for space missions, would be allowed, but the total number of such launchers on each side could not exceed 160. The 160 limit would include all launchers at research and development test ranges and facilities, launchers on “test-bed” submarines and surface ships, and training launchers at operational sites.

C. Further Negotiations

1. There should be a provision that, with a view to amending the agreement, both sides undertake to continue active negotiations on further limiting strategic offensive armaments.

[Page 544]

Part II

Strategic Defensive Systems

A. The agreement should make clear that any system for rendering ineffective strategic ballistic missiles or their components in flight trajectory are prohibited unless permitted by this agreement. The definitions of permitted systems along the following lines should be included in the agreement:

Anti-Ballistic Missiles (ABMs)—i.e., missiles constructed for an ABM role, deployed in conjunction with other ABM components, or of a type indistinguishable from missiles tested in an ABM role;
ABM launchers—i.e., launchers for such ABM missiles;
ABM radars—i.e., radars constructed for an ABM role, deployed with other ABM components, or of a type indistinguishable from radars tested in an ABM role;
Other large phased-array radars—i.e., those of greater than 106 watts-meter2 power aperture product.

B. Limitations


Deployment of ABM systems would be limited to:

100 fixed launchers, 100 deployed ABM interceptors, 4 modern ABM radar complexes and those mechanical-scan, dish-type radars currently operational. All these elements would be deployed within 100 km of one agreed location. Or, alternatively,
300 fixed launchers, 300 deployed ABM interceptors, and 5 modern ABM radar complexes. All these elements would be deployed within 60 km of each of three agreed locations at operational ICBM fields.

The phrase “deployed ABM interceptor” refers to any ABM interceptor located on or in the vicinity of an ABM launcher capable of being fired in a short period of time.

A “modern ABM radar complex” is defined as a circular area of 3 km diameter within which are deployed components of either ABM radars which first became operational after July 1, 1971, or any phased-array ABM radars.

[It should be made clear that the U.S. will agree to only the existing Moscow defense with permitted added components for the USSR and three Safeguard sites defending Minuteman for the U.S.]

[The head of the U.S. Delegation is authorized to fall back, at his discretion, from three agreed sites to two agreed sites. These two sites would have an aggregate of four modern ABM radar complexes and would have 100 fixed launchers and 100 deployed ABM interceptors at each site. All these elements would be deployed within 70 km of each of these two agreed locations. Fall-back from two sites and 200 interceptors is not authorized unless approved by the President.]

The Soviet Union could retain its present 64 ABM launchers deployed in the vicinity of Moscow, and could add up to 36 additional launchers within 100 kilometers of the center of Moscow, to serve a total of no more than 100 interceptors.
Radars would be limited as follows:
The Soviet Union could retain the Dog House radar at Naro Fominsk, the radar under construction at Chekhov, the four active Try Add radar complexes around Moscow, and the two additional radar complexes under construction around Moscow.
Soviet Hen House-type radars suitable for tracking of ballistic missiles would be limited to those currently operational or under construction. [We would inform the Soviets that we regard these radars as tolerable partly in view of their present vulnerability, and that we would consider increased SAM defense of such radars as inconsistent with an agreement.] The U.S. would have the right to build an agreed number of additional early-warning radars to provide capability equivalent to that provided by the Soviet Hen Houses. While such radars would not be designated as “PARs,” it would be understood that PAR components and technology could be used in them.
Limitations would be placed on radars suitable for an ABM role. It would be prohibited for either side to construct additional radar complexes containing: Dog House, Hen House, Try Add, MSR, or PAR types, or other radars specifically designed for ABM use, except as provided in these instructions. There would be agreement to consult in the future on the construction of any new phased-array radar with a power-aperture product larger than 106 wm2 or any smaller radar which might be construed as being ABM-associated. The goal would be to meet legitimate needs of the two countries in ways which did not create suspicion or concern over possible circumvention of the ABM radar limitations.
Upgrading of SAMs (or other types of missiles, whatever their original design mission) to convert them into ABMs, or to give them a dual anti-aircraft and anti-missile capability, or the development of new SAM systems or other missile systems (apart from permitted ABM systems) with such capabilities, would be prohibited. The flight-testing of missiles other than ABMs in an ABM mode (e.g., testing such missiles against a re-entry vehicle in association with ABM radars, or to test air defense missiles in flight regimes inconsistent with air defense threats) would be prohibited. There would be no limitations on SAM systems in their air defense role as such.

C. Corollary Limitations

ABM research and development would be permitted. Each side would have no more than 15 experimental fixed ABM launchers and all ABM systems and system components utilized for research and development and testing would be located within current or agreed additional test ranges.
Development, testing, production or deployment of mobile or transportable land-based, sea-based, air-based, or space-based ABM systems to include ABM missiles, launchers and radars would be prohibited.
Equipping a deployed ABM launcher to handle more than a single ABM interceptor at one time, or to give it a capability for rapid reload through automatic, semi-automatic, or other similar reload mechanism would be prohibited. The development, testing, and deployment of such reload and multiple interceptor equipment would also be prohibited. There would be a prohibition on facilities for rapid reload interceptors, including storage facilities, at ABM sites.

Part III


Verification of the agreement would be accomplished by a combination of reliance upon national means and the provision of corollary limitations and cooperative measures designed to make the overall restrictions compatible with national verification capabilities.

There would be an understanding not to interfere with national means of verification, defined broadly as technical information collection systems necessary for verifying compliance with the agreement operating outside the national territory of the other state, or to undertake deliberate concealment measures which could impede the effectiveness of national means in verifying compliance with the agreement. The prohibition on deliberate concealment measures would not require changes in present U.S. or Soviet practices. The use of covered facilities for fitting out and berthing submarines and surface ships would be prohibited. This prohibition would not bar normal overhaul, conversion, or other work on submarines or surface ships under cover, in accordance with current practices.

Part IV

General Provisions


Joint Commission

Provision would be made for consultations on issues arising out of the provisions of the agreement. A standing Joint Commission would be established to provide a forum to:

Consider questions concerning compliance with the obligations assumed and related situations which may be considered ambiguous.
Provide on a voluntary basis such information as either side considers necessary to assure confidence in compliance with the obligations assumed. Selective direct observation could be offered as a way of clarifying an ambiguous situation.
Consider questions involving unintended interference with national technical means of verification.
Consider possible changes in the strategic situation which have a bearing on the provisions of this agreement.
Consider, as appropriate, possible proposals for further increasing the viability of this agreement, including proposals for additions and amendments.
Consider, as appropriate, proposals for further measures aimed at limiting strategic arms.

The agreement should include a provision wherein neither side would seek to circumvent the provisions and effectiveness of the agreement through a third country.
The agreement should be for an indefinite period with provisions for:
Withdrawal in the event either party decided its supreme national interests were threatened by continued adherence.

The right to withdraw after an initial period of [x] years and upon one year’s notification, if agreement has not been reached on amendments or supplements that provide for additional limitations on strategic systems.

[The President reserves the right to define this period after the outlines of the limitations on strategic offensive systems become clear.]

The agreement should be made subject to formal review at fixed periods. [The length of this period will depend upon the nature of the final agreement.] This would create an opportunity for joint consideration of any changed circumstances, for modification of the agreement if deemed advisable, and for reaffirmation.

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 427, Backchannel Files, Backchannel Messages, 1971, SALT. Top Secret; Nodis; SALT. Copies were sent to the Chairman of the Joint Chiefs of Staff and the senior members of the U.S. SALT Delegation.
  2. See Document 170.
  3. The fifth round of negotiations was held in Helsinki from July 8 through September 23.
  4. All brackets are in the original.