271. National Security Decision Memorandum 1641


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


  • Additional Instruction for the Strategic Arms Limitation Talks at Helsinki (SALT VII)

The President has made the following additional decisions for Helsinki (SALT VII).

[Page 802]

Defensive Limitations

The Delegation is authorized to present the following new proposal on ABM levels in the context of the Soviets agreeing to include SLBM launchers in the Interim Agreement:
Each side may deploy ABM components only within one national capital defense deployment area and one ICBM defense deployment area.
A national capital defense deployment area is a circular area of 150 kilometers radius centered on the party’s national capital. It may contain no more than 100 ABM interceptors/launchers, no more than _____________ Modern ABM Radar Complexes (MARCs), and those mechanical-scan, dish-type ABM radars operational on the date of signature of the treaty. (For the number of MARCs, see paragraph 2.)
An ICBM defense deployment area is a circular area of 150 kilometers radius, containing ICBM silos which are west of the Mississippi River for the U.S. and east of the Ural Mountains for the U.S.S.R. It may contain no more than 100 ABM interceptors/launchers and no more than ______________ MARCs. (For the number of MARCs, see paragraph 3.)
In addition to (but not instead of) MARC limitations for ICBM defense deployment areas, the ABM radars should be smaller in power-aperture than our Missile Site Radar (MSR). However, there would be a specific exception for our Phased-Array Radar (PAR) and MSR now being deployed at Grand Forks. (The Chairman of the Delegation may, at his discretion, propose this as a separate agreed understanding.)
For ABM defense of the national capital, the Chairman of the Delegation may, at his discretion, propose up to eight MARCs.
For ICBM defense deployment areas, the Delegation should continue to press to get Soviet acceptance of the principle of Modern ABM Radar Complexes (MARCs). Moreover, the Delegation should seek to keep the number of MARCs to eight or less per ICBM defense deployment area. However, the Chairman of the Delegation may propose, at his discretion, up to ten MARCs.
With regard to our proposed addition to Article XV of the Joint Draft about withdrawal if the follow-up negotiations fail, the Chairman of the Delegation may, at his discretion, proceed with the scenario outlined by the Delegation. (USDEL SALT VII 1227 as amended by SALT 1235.)2

[Page 803]

Offensive Limitations

The Delegation should seek the inclusion of SLBMs in the Interim Agreement, the effect of which would be the following:
The Soviets, during the duration of the freeze, could have operational or under construction up to 62 modern ballistic missile submarines with no more than 950 SLBM launchers.
In order to reach the numbers above, each new Soviet SLBM launcher on which construction is started, after the freeze date, must substitute for an existing SLBM launcher or an existing older, heavy ICBM.
The U.S. should have the option to replace its 54 older, heavy ICBM launchers (Titans) with up to three ballistic missile submarines and 54 SLBM launchers.
There should be agreed provisions governing the manner in which SLBM launchers would be substituted for the missile launchers to be replaced. (The Delegation should propose, for Presidential decision, appropriate replacements provisions. These provisions should include: (i) notification to the other party when the new SLBM launcher construction begins of what missile launchers will be destroyed or dismantled, and (ii) the procedures and timing for the destruction or dismantling of the old missile launchers. The Delegation should draw upon the work in the interagency paper on “Procedures for Replacement of Old Missile Launchers.”)3
With respect to duration, the Delegation should propose: (i) that the Interim Agreement remain in force for five years unless replaced by a treaty limiting strategic offensive arms, and (ii) that it could be extended by mutual agreement.
The Delegation should continue to press for including our proposed language in Article V/VI regarding covered facilities for submarines.

Henry A. Kissinger
  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 364, Subject Files, National Security Decision Memoranda, NSDMs. 145–264. Top Secret; Nodis; SALT.
  2. The texts of telegram US DEL SALT 1227 and US DEL SALT 1235 are ibid., Box 882, SALT, SALT talks (Helenski) [sic] Vol. 17, January–April 1972).
  3. “Not printed.”