43. Memorandum From the Director of the Office of Science and
Technology Policy (Press) to President Carter1
Washington,
December 2,
1977
SUBJECT
As you requested, I have been getting more involved in some of the
military technology issues. I discussed this with Zbig, and he suggested
that a vulnerability analysis of the M–X
and cruise missile systems would be useful. Subsequently, I convened a
panel of university and industrial experts for this purpose. I have
attached the Executive Summary of the panel’s report on the M–X and will send you a separate memorandum
concerning our cruise missile analysis next week.
The panel examined the comparative vulnerability of the trench-based
M–X system to the silo-based
Minuteman and came up with several interesting conclusions:
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- The threat to Minuteman is not so imminent or certain that
commitment to an alternative system must be made in FY 1979.
- —
- Minuteman will remain a significant survivable component of
the US deterrent throughout most
of the 1980s until the Soviets succeed in developing and
deploying warheads of greatly improved accuracy.
- —
- Due to its complexity, small area of deployment, and technical
aspects of the trench design, the M–X trench system has potential vulnerabilities
which require further assessment and considerable uncertainty
remains in assessments of its survivability.
- —
- In addition to novel basing systems, other less costly options
for enhancing survivability of Minuteman including relatively
simple defensive measures should be more fully explored.
On the basis of these conclusions, commitment to full-scale development
of the M–X trench mobile system as
proposed in the FY 1979 defense budget
request ($260 M) appears premature. I recognize that there may be
overriding political considerations, such as the impact on the domestic
SALT debate and international
perceptions of US resolve, which in your
judgment could necessitate support for the Defense proposal. However, on
the technical merits of the issue, I would recommend that you defer
full-scale development and substantially reduce funding for M–X in the FY 1979 budget, at least down to the level of effort
provided in FY 1978 (about $150 M).
The Panel also noted that a decision to develop a new missile can and
should be made on considerations that are separable from those of
maintaining ICBM survivability. These
include the impact on crisis stability, concerns about aging of the
Minuteman force, targeting requirements and political perceptions. The
panel confined itself to vulnerability analysis for its initial effort,
but if you think it would be useful, we will examine this broader issue
as well.
Attachment
Executive Summary of a Report Prepared by the Vulnerability Panel
of the Office of Science and Technology Policy2
I. The proposed M–X weapons system
includes a missile which is larger, more accurate and carries more
warheads than Minuteman III, and a mobile basing system to make the
missile more survivable.
The proposed M–X funding plan for
FY 79 allocates about $200
M to missile development. This
can be viewed as a commitment to the
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development of a substantially more capable
missile. A decision to develop a new missile can and should be made
on considerations that are for the most part separable from those of
providing a new basing system to maintain ICBM survivability.
II. The vulnerability of Minuteman has properly been a matter of
continuing concern, and it is not too soon to pursue alternatives to
Minuteman silo-basing. However, the threat to the Minuteman is not
so imminent or certain that commitment to the development of a
specific alternative system must be made now.
III. Minuteman will remain a significant survivable component of the
US deterrent throughout most of
the 1980s, that is, until the Soviets succeed in developing and
deploying an adequate number of warheads of greatly improved
accuracy [less than 1 line not declassified].
Such accuracy can be achieved either in a new generation of Soviet
missiles, or by an upgrade in accuracy beyond that now projected in
Soviet systems presently deployed. We are basing this conclusion on
evaluation of the destructive interaction among attacking warheads
(i.e., fratricide), which makes two-on-one attacks very difficult
for purposes other than to increase system launch reliability.
IV. Conceptually, the trench-based M–X system has advantages in survivability over
Minuteman III against attacks of very high accuracy. However, an
assessment of its survivability can only be demonstrated through
calculation and certain limited tests. Considering the complexity of
the system, considerable uncertainty will remain in such
assessments.
Survivability of the M–X relies on
secrecy of location of the missile. If by technical or intelligence
means the attacker can determine, even approximately, the location
of the missile within the trench, the M–X system survivability would be severely
compromised.
Whereas the vulnerability of Minuteman is particularly sensitive to
achievement of high accuracies, as noted above, the M–X is vulnerable to attack by large
numbers of less accurate RVs.
M–X is based on a much smaller land
area than is Minuteman. Therefore, the M–X trench-based system is considerably more
susceptible to “pin-down” under protracted nuclear missile attack
than is Minuteman III. The vulnerability of M–X to pin-down, in combination with a possible
shoot-look-shoot attack on M–X
requires further assessment.
V. In addition to novel basing systems, less costly options, such as
defensive measures, for enhancing survivability of existing
Minuteman silos should be more fully explored, recognizing that the
defended area need be only a few hundred meters across, thereby
allowing the use of relatively simple protection measures.
