114. Letter From Secretary of State Rusk to Secretary of Defense McNamara0

Dear Bob: I greatly appreciated having the opportunity to review the series of memoranda which you have prepared for the President of the FY ‘64 (and forward) Defense Programs. The quality of these memoranda is most impressive and I think the forces, which implementation of the proposals contained therein would produce, are generally consistent with our basic national security policy. In particular, I wish to underline the point which you make in the memorandum on General Purpose Forces1 on the need for strategic lift in the face of the difficulties attending the acquisition of bases in troubled parts of the world.

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I also note that the study of forces required for non-nuclear defense in Europe was predicated on defense of the Rhine.2 In accordance with the conclusion which we reached at the first Defense Policy Conference,3 a study of requirements for a more forward and therefore more politically acceptable defense of the Central Front is under way. I think this is a point well worth mentioning to the President since it could presumably support the need for a subsequent adjustment in General Purpose Force requirements.

Of all of the highly important matters touched upon in your memoranda, to my mind the issue which stands out above all others is that relating to the question of the advisability of deploying an anti-ballistic missile defense. One can only be impressed by the technical complexity of the problem. However, what seems to emerge in this discussion is that a system, having considerable operational uncertainties but, nevertheless, promising significant defensive capabilities under certain conditions, could be deployed beginning as early as 1967, were the decision made at this time to do so. Obviously your technical review, which I gather includes a heavy emphasis on alternative trade-off advantages as between investment in ballistic missile defense and competing weapon systems, inclines you to recommend against a decision to deploy at this time. I gather, however, that this is by no means a black and white issue and, in fact, may represent a rather close balance.

I would have no independent judgment on the technical feasibility/cost consideration factors. If, however, these have led to a negative decision, but only in close balance, then I would think that the decision warrants further review in light of the immense political and psychological implications for our entire security posture over the next decade of a negative decision on deployment. Though undoubtedly taken into account in your decision, the extent to which these implications were weighed is not clear from your memorandum. For that reason, I have set out in a separate enclosure to this letter my own views as to the significance which I attach to the development and deployment by the US of an anti-ballistic missile system in the shorter, rather than the longer, time period. It is my feeling that if such a system, having a reasonable degree of technological effectiveness can be deployed beginning as early as 1967, we should carefully consider the advisability of doing so.

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Since this is a matter of highest importance, you undoubtedly contemplate it as a principal item for discussion with the President. I am prepared to enter into such discussions whenever the President deems it appropriate.

With warm regards,





If the Soviet Union were to deploy an anti-ballistic missile defense system substantially before the United States, such an action could adversely affect the current delicate world power equilibrium and seriously impair the effectiveness with which the US would be able to pursue its national security policy. The basis for this conclusion will be developed in the succeeding paragraphs.

In order to explain the basis for the preceding conclusion, it is necessary to clarify a few assumptions which we make.

We accept the obvious fact that any system of ballistic missile defense which we might choose to develop and deploy is at this point in time fraught with great uncertainties and immense technical complexities. From the memorandum prepared by the Secretary of Defense to the President,5 we would gather that of the two possible systems, Nike Zeus or Nike X, the latter has greater potentialities than the former. Both, however, would seem to embody considerable uncertainties, with perhaps Nike X being more uncertain if only because it is a newer concept having been subjected to a lesser degree of research and development. In any event, however, accepting the current best estimates of system limitations and reliabilities, we would gather that there is a good likelihood that an anti-ballistic missile system could be developed and deployed having a considerable degree of military effectiveness under certain [Page 419] assumptions. (We gather that it is estimated that deployment of 26 batteries might result in survival of as much as 30 to 40% of our population and production base.)

Proceeding from the foregoing, with full recognition of all existing uncertainties, if such a system could be deployed, even accepting its operational limitations, it could have an immense impact on our relations with (a) the Soviets and (b) our Allies.
We do not ignore the significance of the tremendous cost implication. But this is a matter which must be placed in the perspective of the value of what it is we are buying. In this connection, we think we need to re-look at, and perhaps somewhat alter our thinking about, the military exchange ratio problem. It seems to us in considering the value of this weapon system to US security, we must go well beyond the weighing of the technical advantages and disadvantages of investment in alternative weapon systems. Though it is difficult, if not impossible, to precisely quantify, we must introduce political and psychological considerations which will weigh so heavily over the future decade. This is particularly significant in terms of the ability of the US to mobilize public will, both within the US and amongst our Allies, to accept the risks inherent in living in a world of such sharply competing ideologies. Thus, while we appreciate the logic which lies behind the thought that the procurement of offensive ballistic weapons may for sometime to come continue to be far less expensive than procurement of an adequate ballistic missile defense system, this is clearly not the whole story. The essential issue is whether the availability of such a system to the Soviets at a time when the West does not have an equal capability will adversely affect the willingness and, therefore, in a very real sense, the capability of the Western Alliance to effectively contest with the Communists. Or to put the question in another and more positive way, whether the availability of a system to the West, even one having admitted technological limitations, will support and, conceivably, even greatly strengthen our willingness to accept difficult, costly and dangerous undertakings so necessary if we are to preserve and succeed in the contest with the Communists.
From the DOD memorandum it would appear that the Soviets are now in process of deploying an anti-ballistic missile system around Leningrad. While this program may be limited in its present capabilities, we gather that we have no full understanding of its present capabilities or of its ultimate potentialities. It does, however, seem significant that with a stringency on resources which in any real sense is greater than that under which the US labors, the Soviets have chosen to make the beginning which presumably could, if they project and expand their present effort, result in a sizeable Soviet deployment over the next several years. The Soviets are notable for their determination to make military undertakings serve a political end. It would be surprising if their policy in connection [Page 420] with deployment of an anti-ballistic missile system fails to take account of this relationship.
The danger, of course, is that the deployment by the Soviets of an anti-ballistic missile system, during a period when our own defensive posture did not involve such an undertaking, could result in a serious unbalancing of the present power structure, an effort which the Soviets have desperately been trying to accomplish even at the expense of such a risky undertaking as the recent Cuban experience. The change in power balance could occur either because (a) the Soviet system as actually developed proved to be better than we now predict and even conceivably better than the performance which we attribute to our own system (a possibility which however unlikely cannot be overlooked), or (b) because even if the system, in fact, is not as technologically excellent as the preceding assumptions suggest, the Soviets may over-estimate its importance and attempt to use it as a part of a grand political ploy designed to achieve through political means what might not be attainable through actual military means. Either of these two reasons might support a Soviet policy far more active and belligerent than would otherwise be the case. This is not something to be accepted with equanimity.
At the same time, the effect upon our Allies, especially in Europe, of a Soviet attainment of ABM defense in the absence of an equal Western effort, must be carefully assessed. It seems entirely likely that the psychological and political impact would be immense, if not immediately, then ultimately, on peoples living under the daily threat of a massive attack as have our European Allies. Presumably the adverse impact can to some extent be mitigated by explaining the limitations of the Soviet system and pointing up our own immense offensive capabilities (the offense-defense trade argument), but this is unlikely to carry the day. It is well worth remembering, that to the people living under the threat of a massive nuclear missile attack, the fact that it may be sounder economics to buy more offensive missiles than defensive ones, will be vitiated if not entirely lost when it is recognized that only defensive missiles offer the possibility of saving lives.
In view of the foregoing, it is necessary that we consider not only how important it is that we make a decision to deploy an anti-ballistic missile system, but that we also consider the importance of an earlier, rather than a later, deployment. Were the factor of cost not so heavy the answer would be self-evident, viz., that we should proceed with all speed to deploy the first reasonably technically adequate system which is available, namely the Nike Zeus. However, the cost factor is important and in this connection we are struck by the following factors:
That the cost differential between the Nike Zeus and the Nike X, while significant, is not overwhelming. I gather that the former system would cost a total of 15% more than the latter.
That the deployment of the Zeus would apparently not represent a total waste in the sense that the Nike X would be built upon and would in some measure be a logical extension of the Nike Zeus. If this is true, this would seem to me a factor of very great significance. To some extent, especially from the political point of view, it would appear that here is a case where we may be able to have at least some of our cake and eat it too.
If, as is undoubtedly the case, the Nike Zeus has uncertainties as to its performance, presumably the Nike X must be considered a system of even greater uncertainly. If we understand correctly the normal evolution of weapon systems, they invariably demonstrate problems as they move from development through production, problems which are never fully predictable in advance. The further away from completion of development and from initial production, the greater are the uncertainties likely to be. By this standard one might question whether reliance upon the Nike X might not result in even further delay in achieving actual deployment than the two years beyond Nike Zeus estimated for this system’s availability.
Consideration of all of the foregoing factors as they bear upon the conduct of our national security policy over the next several years, gives rise to concern over the prospect of a Soviet deployment of an anti-ballistic missile system in the absence of a similar US action. Even if each of the systems have some technological limitations as the DOD studies contemplate to be the case, the political and psychological impact of having, or not having, a system to offset that of the Soviets, would be immense. Thus, even if the Sputniks had no military significance whatsoever, the mere fact that the Soviets were able to orbit their vessel in space before we were, created a serious liability under which we labored for sometime and under which we still labor to some extent even today. Indeed in such circumstances the tendency of the US is to try to overcome lost time through an accelerated effort which may not always result in the most economical use of funds and which can never fully regain lost political ground. This is a prospect which cannot be ignored when considering the anti-ballistic missile problem. It is possible that with the availability to the Soviets of an ABM defense the political and psychological pressures will become so great that we will have no alternative other than to launch an emergency deployment of a system having thereby sacrificed the opportunity to gain a favorable impact through an earlier voluntary undertaking and at the same time having to accept what may be a less economical solution to the problem.
There is one last aspect to the problem which, so far as we are aware, has not received any prior consideration. This has to do with the possibility and utility of considering the eventual extension of an anti-ballistic missile system to Europe. As previously indicated, as Soviet [Page 422] capabilities in this field are developed and begin to grow, the pressures upon our European Allies to have a missile defense will mount. The political pressure within the countries will unquestionably be reflected in the make-up of governments and in the manner and extent to which governments can function effectively in support of policies which the US believes important. Even if we are ourselves convinced of the limitations of a ballistic missile defense it is the advantages and virtues of such a system which the Europeans will emphasize. As with the problem of the lack of European knowledge about nuclear weapons and the effects of their employment which now plagues us in our efforts to gain a common strategic concept with our Allies, so too a failure to hold open the promise of a ballistic missile defense may have an analogous effect. While the tremendous cost involved will always represent a practical inhibition to active European interests in this area, we do not think we can exclude or downgrade that interest solely on those grounds. To the contrary, particularly if the US were to encourage the notion that a considerable degree of defense could be bought through deployment of an anti-ballistic missile system, it seems not improbable that the Europeans might well be inclined to invest considerable resources to this end. We recognize, of course, that to some extent this could be counter-productive insofar as it drains away European resources from other defense expenditures, which, from our point of view, we would prefer to see them make. It might, however, have a contrary effect by draining away resources from low priority defense programs. Whether we like it or not, however, the pressures are quite likely to exist. Either we will be able to satisfy them at least to some extent, or we will have to pay the possible serious political price of not being able to meet what the Europeans will probably consider to be a legitimate requirement.
  1. Source: Washington National Records Center, RG 330, OSD Files: FRC 66 A 3542, 452 10 Jan 62. Top Secret.
  2. For the final version of this memorandum, see Document 115. Regarding an earlier draft, see footnote 4, Document 107.
  3. This discussion occurs in the section of “US Non-Nuclear Force Requirements Worldwide,” which also notes that “the Joint Chiefs believe that military strategy must be based on containing the enemy well forward, placing his forces in jeopardy, and assuming an early counter-offensive, rather than allowing him to take a sizeable amount of territory that can be used as a fait accompli in any pause negotiations.” This language paraphrases part of a September 30 memorandum from the JCS to McNamara. (Washington National Records Center, RG 330, OSD Files: FRC 66 A 3542, 110.01 Project #22)
  4. See footnote 5, Document 86.
  5. Top Secret.
  6. Document 111.