113. Memorandum From the President’s Assistant for National Security Affairs (Brzezinski) to Secretary of Defense Brown1
SUBJECT
- M–X Survivable Basing (U)
Given the broad range of political, military and arms control implications that the M–X basing mode decision will have, the President will be interested in having an NSC meeting in early April to review [Page 534] your recommendation as well as the analysis upon which it is based. I thought it would be useful, therefore, to describe the sorts of information that we would like you to forward as a basis for this meeting. (S)
I believe the President would like to see a side-by-side comparison of four options: the air-mobile option that you have recently asked the Air Force to develop; the MPS option they are also working on; the off-road mobile option we have discussed on previous occasions; and finally, on the possibility that none of the above options seems acceptable, an option that combines whatever improvements can be made to the silo-based ICBM force and significant new efforts to improve the bomber and SLBM forces. (S)
The side-by-side comparison we have in mind should evaluate the various options according to all the standard criteria—costs, technical risk, IOC, survivability, etc. It should take particular care to answer the following specific questions:
- —
- How do the basing schemes differ in their abilities to support the flexibility, endurance, and targeting capabilities required to defeat possible Soviet objectives in a nuclear war? How do they differ in their ability to serve as a basis for rapid expansion of our strategic forces, should such a need arise?
- —
- Within the likely constraints of SALT, what are the most effective Soviet options for reducing the survivability of each new basing scheme? In the face of such Soviet responses, what would be our most effective options for maintaining the overall survivability of our strategic forces? What are the economic and other costs of such responses and counter-responses? (S)
- —
- Assuming that our adoption of each basing scheme leads the Soviets either to deploy a similar scheme or to deploy the scheme that is most cost-effective for them, in what ways would the existence of this new Soviet system make it easier for the Soviets to break out from SALT and upset the strategic balance? (S)
- —
- In what ways might the adoption of each basing scheme lead to difficulties for each side in determining the strategic forces capabilities of the other side, or in verifying arms control provisions of the kind embodied in SALT II or possible future agreements?2 (S)