Office of the Historian

60. Memorandum From the Director of the Office of Science and Technology Policy (Press) to President Carter1

Washington, May 1, 1978

SUBJECT

  • M-X and Minuteman Vulnerability

There is growing acceptance within the Pentagon of the conclusion of our OSTP Vulnerability Panel last fall2 that a commitment to full-scale development of the M–X trench mobile system would have been premature since there were major unresolved vulnerabilities in this system. A Defense Science Board task force has completed a preliminary analysis of the M–X trench system and has concluded that “it has disadvantages compared with other proposed concepts sufficient to rule it out in our view.”3 As a result, emphasis in the Pentagon is shifting to other multiple aim point systems such as building a large number of silos (perhaps twenty) for each ICBM so that the Russians would have to expend a very large number of RVs to threaten our land-based ICBM force.

Like the M–X trench system, these alternatives may involve verification as well as vulnerability problems. For example, the multiple silo system would require modification of SALT limitations on numbers of launchers and on-site inspection to verify the numbers of missiles [Page 261] actually deployed. Other alternatives such as placing a bigger missile with a larger number of RVs in current Minuteman silos; developing defensive measures for Minuteman; or shifting more of our strategic deterrent to the SLBM and cruise missile forces also need to be thoroughly examined.

Nevertheless, there may be growing urgency in reaching a decision on ICBM modernization as a result of recent flight tests by the Soviets of new SS–18 and 19 RVs which appear to have significantly improved accuracy. The degree of improvement in these new systems is uncertain since analysis of data has not been completed; however, it seems clear that Minuteman may be seriously threatened on an earlier timescale than projected in our report. As a result, I plan to reconvene my Panel in the near future to examine Minuteman vulnerability in light of these developments and to consider alternatives for ICBM modernization.4

  1. Source: Carter Library, National Security Affairs, Brzezinski Material, Brzezinski Office File, Subject Chron File, Box 124, Weapons Systems: 4–9/78. Secret. Carter initialed the upper right corner of the memorandum.↩
  2. See Document 43.↩
  3. Carter wrote “I agree” in the right margin next to this sentence.↩
  4. Carter wrote “good” in the right margin next to this sentence.↩