203. Memorandum From Secretary of Defense Brown to President Carter1
I attach a copy of a memorandum from the Joint Chiefs of Staff on
(PD)/NSC–38, announcing your decisions as to the U.S. negotiating [Page 489] position on CTB. They have asked that I forward it to
you, as an expression of their strongly held views. I believe that the
JCS memorandum accurately
identifies the technical and military factors involved. I agree with
some, but not every one, of their evaluations.
A CTB involves some level of military
risk. However, I believe that the probability that a CTB would adversely affect the reliability
of the warheads for our important strategic systems is low enough during
a three-year (or, less clearly, even a five-year) period so that for
such a period the military risk in itself is acceptable. Of some weight
also is the fact that we would become aware by continued stockpile
inspection if a question of such reliability arises and, in principle,
could invoke the supreme-national-interest withdrawal clause.
I emphasize that there would be a serious question of continued stockpile
reliability on the U.S. side if there were an indefinite CTB.2 The greatest
risk, therefore, follows from the tendency of a limited-term agreement
to be extended. The statement of intention to resume tests at the end of
a limited-term in order to assure stockpile reliability can somewhat
ameliorate that problem. But the pressure at the time of expiration to
renew (and also pressure not to do so) will probably be very great
despite anything we say now. Such a concern about extension is likely to
be expressed by opponents during the ratification process. This aspect,
in my judgment, makes the prospects for approval of a CTB substantially less favorable than
those for SALT, and also less
favorable the earlier a CTB is
concluded.
[1 paragraph (3 lines) not declassified]
I believe that the JCS paper understates
the potential advantages from a CTB for
non-proliferation (which many of us see as its main benefit). However,
those advantages have yet to be articulated sufficiently. In my view it
would be useful for the State Department and ACDA to set forth the criteria by which they believe we
would be able to judge after a five-year period whether proliferation
had indeed been inhibited by the CTB,
and therefore whether there would be reasons supporting renewal to
counter the military and technical needs for reliability tests.3
A great concern of mine is the possible irretrievable dissipation of our
nuclear scientific and technological talent if a CTB is perceived by them as being of long
or indefinite duration. To be able to test for stockpile reliability
after a previously set time period of some years, and to correct
deficiencies, the capabilities of the nuclear design laboratories [Page 490] have to be maintained. From
this point of view there are two matters that particularly trouble me.
(1) The decision to limit experiments to a few pounds4 of high explosive equivalent—rather than, for
example, a few hundred tons5—limits sharply the degree of interest
of such experiments to the scientists and technologists on whose
continued skills and continued professional dedication to nuclear
weapons design we would depend when tests are resumed. (2) Second, the
five-year period of the treaty instead of a three-year period that had
alternatively been proposed also reduces the chances of keeping viable
nuclear laboratories together. The laboratory directors have told the
JCS that, given a commitment to
resume testing, they can maintain relevant laboratory effectiveness for
three years, but probably not for five. I therefore urge that these two
issues be reexamined as part of the development of the safeguards
program you requested by June 30.6
Attachment
Memorandum From the Chairman of the Joint Chiefs
of Staff (Jones) to Secretary of Defense Brown
7
JCSM–188–78
Washington, June 1, 1978
SUBJECT
- Presidential Decision on Comprehensive Test Ban (U)
1. (S) Presidential Decision (PD)/NSC
388 announced that in view of the importance
of maintaining confidence in safety and reliability of US stockpiled nuclear weapons, the
President has decided that the United States should propose a
fixed-duration Comprehensive Test Ban (CTB) treaty of 5 years, with provision for nuclear
weapon experiments of a few pounds yield. In forwarding the treaty
to the Senate for ratification, the President would state that the
United States intends to resume testing at the expiration of the
treaty, for safety and reliability purposes only, unless testing is
shown not to be necessary. Any further [Page 491] agreement on testing limitations after the
5-year treaty would be presented to the Senate for ratification.
2. (S) The Joint Chiefs of Staff consider that the test ban, as
outlined, would involve significant military risks. In a
memorandum9 which you forwarded to the President on 22
April 1978,10 the Joint Chiefs of Staff stated
they believe that a test ban must allow continued testing at a level
sufficient to:
a. Maintain high confidence in the reliability of US nuclear weapons and hence confidence
in the US nuclear deterrent.
b. Avoid undesirable asymmetries which are otherwise likely to result
due to the inability of the United States to verify compliance with
the test ban.
3. (S) Recent discussions which the Joint Chiefs of Staff have held
with Department of Energy officials and their laboratory directors,
upon whom the United States must rely for technical judgments
concerning the reliability of US
nuclear weapons, have further underscored the requirement for
continued testing to maintain stockpile reliability. These experts
have stated that, under a CTB with
zero testing over an extended period, stockpile reliability will be
degraded. They have taken the position that the most current nuclear
warheads and bombs in the US
stockpile cannot be maintained without nuclear testing. Their
current best estimate is that the required nuclear yield for that
purpose is at [less than 1 line not
declassified] With nuclear testing permitted at [less than 1 line not declassified] it is
likely that the current nuclear weapon stockpile could be maintained
in a safe and reliable condition. The Joint Chiefs of Staff have
found these assessments persuasive.
4. (S) Based on available information, Soviet reliability problems
may not be as severe, since the Soviets’ typically heavier weapons
and larger payloads have allowed them to use coarser design criteria
which are not as susceptible to problems as the high-technology
US designs. This is likely to
cause an asymmetric degradation of the stockpiles. Assuming that the
Soviets recognize this, they may eventually perceive a strategic
advantage, and the asymmetry therefore would become
destabilizing.
5. (S) The announced intention to restrict resumption of testing to
that necessary for weapons safety and reliability appears to preempt
decisions concerning weapons development which are better made in
the context of other arms control agreements. The United States may
be [Page 492] unilaterally
restricting development of new strategic weapons, without any
similar restraint upon the Soviets if a SAL agreement or other
agreements reached do not restrict new strategic weapons
development. Moreover, such an unfavorable asymmetry may also be
imposed on the development of new theater/tactical nuclear weapons,
at least until an arms control agreement with reciprocal restraints
might be achieved.
6. (S) [10 lines not declassified] Thus, the
United States will face a situation wherein the Soviets could test
without detection and the United States will not test—a situation
that could lead to asymmetries detrimental to the credibility of the
US deterrent.
7. (S) Experience with the nuclear stockpile has demonstrated that
serious problems can arise during a 5-year ban on nuclear testing.
The decision in PD/NSC 38 does not provide for testing to address
stockpile reliability problems which may arise during the period of
the treaty. In the event that a serious problem arises, the United
States would either have to exercise the “supreme national interest”
withdrawal clause or depend on a less reliable deterrent force. The
Joint Chiefs of Staff believe that, rather than accept the prospect
of placing the United States in this undesirable situation, the
United States should initially seek to negotiate a treaty which
lowers the testing threshold to the level of verification
capability. Such a lowered threshold could provide an opportunity to
learn how to deal more confidently with stockpile reliability
problems in an environment of restricted testing, while at the same
time observing Soviet performance under the treaty and upgrading
US monitoring capabilities.
8. (S) JCS discussions with the
nuclear laboratory directors also have confirmed the belief of the
Joint Chiefs of Staff that retention of skilled scientists and
engineers at the US nuclear weapons
laboratories is essential to maintain the stockpile and retain a
nuclear weapons design capability. The Joint Chiefs of Staff concur
with the judgment of the laboratory directors that it is unlikely
that the necessary number of skilled scientists and engineers can be
retained throughout a 5-year test suspension, even under the
incentives of a strong safeguards program.
9. (S) In addition to the military and technical considerations
expressed above, there are also politico-military implications which
should be given consideration. The Joint Chiefs of Staff recognize
that it is in the US national
interest to stop nuclear proliferation. However, they are not at all
certain the balance of considerations with respect to a test ban, as
outlined, would contribute substantially to nonproliferation.
Further, if US allies were to lose
confidence in the ability of the United States to maintain a
credible and reliable stockpile and, hence, in the deterrent quality
of US nuclear guarantees, they could
be disposed to develop or increase nuclear stocks.
[Page 493]
10. (S) The Joint Chiefs of Staff judge the military risks to
national security to be serious. The issue is considered to be the
adequacy of the US nuclear deterrent
forces—both perceived and actual—and the equivalence of those forces
to those of the Soviet Union. The magnitude of the risks and the
potential consequences compel the Joint Chiefs of Staff to conclude
that the negotiating position could result in a treaty which would
adversely affect the national security interests of the United
States.
11. (S) The Joint Chiefs of Staff request that you forward this
memorandum to the President.
For the Joint Chiefs of Staff:
David C. Jones
General, USAF
Acting Chairman
Joint Chiefs of Staff
