Foreign Relations of the United States, 1977–1980, Volume IV, National Security Policy

146. Memorandum From Fritz Ermarth and Charles Stebbins of the National Security Council Staff to the President’s Assistant for National Security Affairs (Brzezinski)¹

Washington, August 6, 1979

SUBJECT

• PRC on M–X Basing Mode (U)

Tomorrow Harold Brown will recommend to the PRC that the M–X be deployed in a mode involving multiple horizontal shelters among which the launcher could be moved surreptitiously or, in extremis, dash on warning. The basing concept is adequately described at Tab A.² (S)

All in all, we believe the DOD has come up with a satisfactory basing mode against the difficult criteria of survivability, verifiability, environmental impact, and cost. State, ACDA, and OMB are expected to endorse the DOD recommendation. Admiral Turner may raise two points of criticism (noted below). We recommend that you express support of this basing mode and believe the PRC can promptly make this recommendation to the President. (S)

This memo highlights certain issues and data you may find useful in the meeting. (U)

Survivability

The DCI may argue that the proposed baseline deployment of 4600 shelters could be swamped by large numbers of Soviet ICBM RVs in the late 1980s. Tab B displays his tabulation of possible Soviet RV threats as extracted from the latest NIE.³ These threat levels are physically possible. But that possibility does not obviate the viability of the multiple-aim-point basing approach.

— Under SALT II limits, assuming they are extended into the late 1980s, the attacker would fall short of weapon numbers required to kill M–X and Minuteman, or have just about enough. In any case, he would have virtually to exhaust his ICBM force in order to swamp our baseline deployment.⁴

— With or without SALT, if we see a proliferating RV threat, we can expand the number of aim points at from $1.7M to $2.2M each. Additional deployed RVs probably cost the Soviets on the order of $3–5M each if the missile force is expanded. Buying more RVs through fractionation would cost them on the order of $1–2M per RV.

— Should SALT II limits break down, SALT III fail, and we see the Soviets trying to swamp our expanding set of aim points, this would signify a kind of competition in which current constraints would surely be relaxed. We would be much more willing to consider:

• Hard-point preferential ABM defenses for M–X.

• Launch-under-attack options that could be more effective in the late 1980s against a 5000+ RV raid into a small area than such options are today as a response to Minuteman vulnerability.

• M–X mobility outside confined areas.

The point is that there are no perfect, good-forever answers to this or any other strategic problem. Insisting on them tends to mean opting out of the competition. (S)

Verifiability

DOD, State, ACDA and CIA staff believe the DOD basing concept would be verifiable if deployed by the US or the Soviets. Admiral Turner reportedly has residual concerns about verifying a Soviet version. He fears they might try to slip a small highly mobile missile into the system as an evasion or breakout approach. This is possible, but would have to be in large numbers to matter. Moreover, this is a risk no matter what we do with M–X. Only a complete and tightly policed ban on all mobile missiles of strategic size could eliminate this problem . . . and that might not be enough. (S)

People in the Area and Security

You raised a question this morning about “campers along the dash road.” Under normal peacetime conditions, the missile TEL would move but once every six months or so. This would leave plenty of time to clear intruders from any specific confinement where a missile is being moved. Even a “rapid shuffle” (complete relocation over some 12 hours) would allow enough time to clear roads. In a crisis, deployment areas could easily be cleared. Only in the case of a large-scale dash on tactical warning might there be some chance of running a camper off the road. Incidentally, the average camper, jeep, etc., could outrun the M–X TEL at its maximum 20–30 mph speed. Each unit would have 5–8 people with it for operation, security and other functions. (S)

Costs for SALT

There is some concern that we are buying a horizontal basing mode ($26.9B acquisition costs) that is more expansive than vertical MPS ($21.1B) largely for SALT verification reasons. Some may be unwilling to pay $6B to solve a verification problem the Soviets don’t really have. In actuality, the extra $6B buys a mixture of increased verifiability and increased survivability through rapid shuffle and dash capability. At most, $1–2B less would be spent if we wanted horizontal shelters but didn’t care about verification. Registering the principle that systems can and should be designed for verifiability is worth it if the Soviets follow suit. (S)

Acceleration Option

At Tab C⁵ is a US AF point paper that argues we could possibly have IOC as early as early 1985 and also save $1.2B in total system costs. The burden would be some $6B in added FY 81–84 funding. This option should be discussed at the PRC, further examined, but not immediately decided. It has political and strategic attractions. But it would further warp the budget in favor of strategic spending when, with M–X now moving, general purpose programs may be more deserving. This should be resolved in the context of new defense budget levels. (S)

Presidential Decision

You may wish to discuss the possibility of having the President announce the basing mode decision at the beginning of a press conference in order to identify himself with strong defense and strategic equivalence. The President’s tone should be one of fiscal sacrifice in order to relieve Soviet-induced pressures on our land-based ICBM force. A PRC recommendation to the President that he make the announcement personally would be persuasive. (S)

1. Source: Carter Library, National Security Affairs, Brzezinski Material, Brzezinski Office File, Subject Chron File, Box 125, Weapons Systems: 8–12/79. Secret. A stamped notation in the upper right-hand corner of the memorandum reads: “ZB has seen.”
2. Attached but not printed is a July 23 paper prepared in the Department of Defense, entitled “The Horizontal Dash MX System.”
3. Not found attached.
4. A marginal note at the bottom of the page reads: “sheltered reinforced truck-mobile system.” The word “reinforced” was struck through.
5. Not found attached.