105. Memorandum from Brown to
McNamara, March 201
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SUBJECT
- Joint US–UK Technical Discussions
on Nuclear Test Ban Questions
At the urgent request of Prime Minister MacMillan a group of British
scientists led by Sir Solly Zuckerman met with U.S. scientists on
Saturday and Sunday, March 17–18. The stated purpose of the meeting was
to reach an agreed position on the scientific aspects of nuclear test
ban control.
The meeting was a meandering affair touching on numerous scientific
questions. It appeared to DOD
representatives present, however, that the principal matter of interest
to the British was the adequacy of national or unilateral seismic
detection systems to monitor an underground test ban agreement. The
simplest interpretation of British intent is that they are seeking
scientific support for a proposal of a test ban agreement without
international controls of the sort which the U.S. has always considered
necessary.
In the course of the meeting no technical results were presented by
either the U.K. or U.S. scientists to indicate that the problems of
underground test detection had been solved.
A decision at this time to enter into a test ban agreement with only
national systems for control would be a purely political decision, not
warranted by any change of the technical situation.
I recommend that you oppose any move in this direction, in view of:
(a) the continuing need to prevent an imbalance in nuclear weapons
development. Though underground testing is limiting, it does allow gains
and could be hidden without inspection as a safeguard.
(b) the very bad precedent any treaty based on national systems would set
for future disarmament agreements.
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Attachment
March 18, 1962
DRAFT AGREED CONCLUSIONS OF US-UK TECHNICAL MEETING ON NUCLEAR TEST DETECTION
1. That Western unilateral detection systems can currently detect
seismic events in the USSR of
magnitude 4.75 or slightly less. This will lead on the average to
detection of about 125 shallow seismic events per year within the
USSR.
2. That the proposed Geneva system is predicted to detect seismic
events down to 3.75 magnitude, which implies detection of about
1,000 shallow events per year in the USSR. This system could not be available much before
1965.
3. That improvements of detection by unilateral systems to perhaps
magnitude 4.2 in the USSR is a
reasonable technical goal for 1965. This, we now believe, implies
detection of 300 shallow seismic events per year within the USSR. Among the research areas of
particular promise are use of deep hole detection systems and
correlation of
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data from phased arrays.
4. That a unilateral system can currently locate detected seismic
events to within a radius of from 10 to 20 km.
5. That, with utilization of data from an improved internal USSR seismic detection system for the
purpose of calibrating the external system, the location capability
of an external unilateral system might improve to the point where
location to within a radius of ten km. or less in seismic areas
would be feasible. This conclusion is predicated on the assumption
that the USSR data are not
falsified.
6. That at present it is impossible unilaterally to identify shallow
seismic events in the USSR as
earthquakes, excepting at large magnitudes, but that future
improvements, in particular ones involving processing of data from
large arrays, offer hope of reducing the magnitude at which
identification of some earthquakes is possible down to about
magnitude five. There does not appear
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to be any prospect of
identifying a given event as an explosion by seismic means
alone.
7. That if a unilateral system (for example a non-Soviet system for
detecting events within the USSR)
is to be used as a basis for initiating inspections, it will be
necessary to agree on objective criteria which will determine
eligibility for inspection and to establish a mechanism for
certifying the eligibility of a given event. Although these problems
were discussed no specific proposals have been formulated.
