111. Letter From Secretary of Defense Laird to the President’s Assistant for National Security Affairs (Kissinger)1
As I indicated in our telephone conversation earlier today,2 I am seriously concerned about the Minuteman survivability question and the tremendous cost implications associated with insuring its invulnerability in the face of the growing Soviet counterforce threat.3
In my view, it is particularly important for the President to address this question and be aware of its central importance with regard to our negotiating position at Helsinki and our overall strategic posture for the future.
The negotiating proposal defined by NSDM–744 and tabled at Vienna contains provisions which, in their aggregate, preclude all effective measures by which the United States could provide fixed land-based ICBM survivability in the long term. At the same time, this proposal does not preclude the improvements to Soviet ICBMs which could result in a credible first strike threat to Minuteman.
Recent intelligence indicates that the Soviets are vigorously developing a payload for the SS–11 with three re-entry vehicles and the potential for improved accuracy. The character of this development, which was not specifically forecast last year, suggests it is designed to penetrate Safeguard. We cannot discount the possibility that this SS–11 program is intended to evolve into a MIRV capability against Minuteman.
The Soviets have also resumed testing of the triple re-entry vehicle payload for the SS–9, which we have regarded as a possible counterforce weapon against Minuteman. There is little doubt that the Soviets could deploy an accurate MIRV system with a greater number of warheads in the 1972–74 period which would give one SS–9 missile a clear capability to destroy more than one Minuteman silo.
The successful development and deployment of accurate MIRV payloads on the SS–9 and improvements in SS–11 accuracy, even with the limitation on the number of launchers in the NSDM–74 proposal, [Page 356] could give the Soviets the capability by the mid-70s to destroy most of our Minuteman silos unless we take timely measures to increase their survivability or make a conscious decision to concede potential Minuteman vulnerability as a trade-off to permit acquiring additional offensive capability.
1. Improving Minuteman Survivability
Possible measures for long term improvement in Minuteman survivability include relocating Minuteman into hard rock silos, defending Minuteman fields with Safeguard or other ABM defenses (i.e., “hard point defenses”), or placing Minuteman missiles on mobile launchers. We do not yet have full technical confidence in the feasibility and adequacy of any of these measures. Some combination may be required. But the present formulation of the NSDM–74 proposal prohibits them all, except for the option to relocate 250 silos, or to replace Minuteman land launchers on a one-for-one basis with sea-based launchers or bombers. This proposal does permit the hardening of existing Minuteman silos, but this measure is only an interim solution which can be overcome by continued improvements in Soviet missile accuracy and MIRV payloads.
2. Other Alternatives
As noted above, NSDM–74 does provide for the replacement of fixed land-based ICBM capability with other systems within overall limitation on strategic delivery vehicles. This “freedom to mix” would permit the construction or retention of bombers, the relocation of Minuteman to a mobile platform afloat, or the substitution of other sea-based ballistic missile capability (surface or submerged platform), should such a path be indicated by developments in a threat to Minuteman.
Under the current SALT options, there appear to be three ways to approach the Minuteman survivability issue. First, the most desirable to an arms control agreement remains the reduction approach embodied in our earlier Option D.5 This option provides for mutual U.S.-Soviet reductions in the number of land-based strategic delivery vehicles over the next five years and, therefore, would allow us to reduce our most vulnerable systems without incurring a numerical disadvantage. It could also result in reduced strategic force budgets, whereas savings are less likely under NSDM–74 provisions. Even though the negotiability of Option D is questionable, we should keep it as an active proposal.[Page 357]
If we were successful in negotiating Option D, then the problem of Minuteman survivability would essentially be solved by negotiations.
On the other hand, if Option D did not serve as a basis for agreement, and we proceeded with Option E, we still retain the flexibility of adjusting our force mix, should the Soviets give indications that they are continuing to pursue a capability to destroy fixed land-based ICBMs. This is the second alternative.
A third approach is to modify NSDM–74 to permit land-based mobile launchers in addition to the other options noted above. Presumably, such an option might be acceptable to the Soviet Union, since its “basic provisions” would allow mobiles, but this would require modification of our negotiating position and severely complicate verification requirements. We could also propose other changes in our negotiating position such as permitting a hard-point ABM defense of fixed silos.
In sum, the issue revolves around our commitment to the invulnerability of fixed land-based ICBMs. If it is national policy to remain committed to the invulnerability of our fixed land-based ICBM force, then the provisions of NSDM–74 could cause us severe problems. If, on the other hand, we adhere to the “freedom to mix” concept of NSDM–74 and take steps to insure that we can preserve our offensive capability by this means, then we need not be overly concerned about a developing Soviet counterforce capability.
The concern about fixed land-based missile vulnerability can be viewed as a major trap or a major opportunity. Given the current situation—namely, approval of Safeguard for Minuteman defense only; recognition that such defense may not be adequate or justified in itself for only Minuteman protection; our SALT position; and the increasing threat—a continued commitment to the invulnerability of fixed land-based ICBMs could become a major trap. We could be faced with a situation of devoting substantial and scarce resources to preserving the current capability in Minuteman at the expense of added offensive capabilities in the face of a growing threat.
Convincing Congress of the need for devoting an ever-increasing percentage of scarce strategic dollars to defense of Minuteman alone with no apparent guarantee that the defense can keep up with the offensive countermeasures poses difficult problems indeed.
On the other hand, we could take advantage of the current situation and use it as a major opportunity to make carefully reasoned and politically acceptable adjustments in our forces; or we could take steps this year to preserve the flexibility to do so through appropriate options. Either course could be a clear signal to the Soviet Union, a signal that we recognize that they are developing such a counterforce capability, but that we can bypass the problem through appropriate [Page 358] alternative force decisions which do not contemplate a defense of Minuteman at any cost. NSDM–74, as now written, does permit the latter action.
Henry, I have given considerable thought to this problem and several others relating to our broad National Security Strategy for the 1970’s and beyond. I will be communicating with the President and with you on the broader aspects of our strategy in the near future but in light of the resumption of talks next week in Helsinki, I thought it important to bring this aspect of the problem to your attention at this time.
- Source: Washington National Records Center, RG 330, OSD Files:FRC 330–76–076, Box 12, USSR, 388.3. Top Secret; Sensitive.↩
- No other record of their conversation has been found.↩
- On October 27 Tucker sent Laird a memorandum concerning Minuteman survivability in response to an NSC request for a study of the vulnerability of all strategic offensive systems. (Washington National Records Center, RG 330, OSD Files: FRC 330–76–076, Box 12, ???????.)↩
- Document 100.↩
- See the enclosure to Document 68.↩