151. Memorandum from Director of Central Intelligence Turner to the President’s Assistant for National Security Affairs (Brzezinski)1
SUBJECT
- Comments on Proposed MX Basing Mode From an Intelligence Point of View
1. Attached are two sets of comments on the proposed MX basing concept.2 One covers considerations of verification which are relevant to this system and responds to your memorandum of 13 August;3 the other addresses possible Soviet responses to the deployment of an MX system. Both are summarized below.
2. Monitoring:
- a.
- Objectively the Soviets should be able to monitor with high confidence the MX system as currently proposed by the Secretary of Defense.
- b.
- The Soviets will probably not actually feel quite that confident.
- c.
- The Soviets will very likely continue to protest that this basing mode is not verifiable.
- d.
- Should the Soviets deploy an identical system, we believe that we could monitor the number of MX type missiles deployed in it with high confidence; there are, however, possibilities for cheating [1 line not declassified] The Soviets are not likely to view this cheating possibility as an attractive option.
- e.
- A Soviet multiple protective shelter system would likely differ in some respects from the US proposal, and our monitoring confidence would depend heavily on the characteristics of that system.
3. Soviet response: [4 lines not declassified] The proposed baseline MX basing system would have 4,600 shelters, or aim points by 1989. The following tabulation shows how many RVs the Soviets could have in excess of the number required to attack all Minuteman silos, the baseline MX system, and command and control facilities in the US. This is not intended to imply that the US should or would need to build this many shelters, but it does serve to illustrate the scope of the problem the Soviets might create.
[Page 693]| Case | Excess Soviet RVs Following Attack on Minuteman, Command and Control, and Baseline MX |
| 1. Moderate Soviet effort within SALT II | −310 |
| 2. High Soviet effort within SALT II | 2,140 |
| 3. Moderate Soviet effort if SALT II fails | 3,130 |
| 4. Accelerated Soviet effort in 1986 if SALT II RV limits expire | 2,750 |
| 5. Accelerated Soviet effort after abrogating SALT II in 1982 | 4,620 |
| 6. High Soviet effort if SALT II fails | 8,490 |
While it is difficult to predict which option the Soviets may elect, it is clear that they do have options which at the least would apply pressure on us to seek continuation of the limits on RVs (Cases 1 and 2).
4. Detailed back-up analysis is being performed and will be made available as soon as possible. This report is forwarded preliminary to that to meet the deadline requested in your reference memo.