101. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon1

  • SUBJECT
    • Soviet SS–11 Modification

Since July 23, the Soviets have carried out seven tests of a modified SS–11. The evidence points to the testing of two improved pay-loads for the SS–11 ICBM, one very possibly carrying multiple reentry vehicles (MRVs) or penetration aids.

The Test Evidence

The intelligence evidence on the seven modified SS–11 tests indicate that a MRV or penetration aids were probably tested on the third and sixth of the tests. The other five tests involved only the testing of a single RV, possibly one with increased accuracy.

While it is possible that our intelligence is misleading, the Soviets are probably testing both an improved single RV and a MRV payload for the SS–11. However, intelligence evidence is not yet precise enough to specify the performance characteristics of either new payload.

The most likely Soviet plan would seem to be to give some SS–11s a capability to destroy our ICBMs through improved accuracy and to give some SS–11s a capability to penetrate our defenses with MRVs or penetration aids. With 830 SS–11 missiles deployed or planned for deployment, the Soviets could substantially improve the effectiveness of their ICBM force through such modifications.

Deployments of the SS–11

Besides testing a modified SS–11 ICBM, the Soviets have also tested an unmodified SS–11 at intermediate range, and started construction of 70–100 SS–11 silos at intermediate/medium range missile (IR/MRBM) fields in Western Russia.

The most recent NIE2 concludes that the SS–11 missiles to be deployed at IR/MRBM complexes are intended for use at IR/MRBM [Page 354]range against NATO. The Soviets could plan to modernize and harden their IR/MRBM forces by replacing the missiles now deployed, particularly those at soft sites, with SS–11 silos.

The Soviets have already deployed a large and effective IR/MRBM force targeted on NATO. If they plan further increases in their MR/IRBM forces, their incentive is not apparent. Since an unmodified SS–11 could cover most U.S. targets from the IR/MRBM launch complexes, the Soviets may be deploying the SS–11 for use as an ICBM despite its location in IR/MRBM complexes and recent testing as a MRBM.

Summary

Since 1968, our understanding of SS–11 testing and deployments has been inadequate. The Soviet development of an improved SS–11 ICBM payload, particularly involving the use of MRVs or incorporation of accuracy improvements, has not been clearly anticipated and may have been dangerously discounted.

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 845, ABMMIRV, MIRV Panel Meeting. Top Secret; Sensitive; [codeword not declassified]. Sent for information. Although no drafting information appears on the memorandum, Lynn sent a draft to Kissinger under a covering memorandum. (Ibid.)
  2. Document 46.