DECLASSIFIED ---· Au iicr y I r E J 2f 'i _ ByLCV NAPA · · - - - Datcl' ' f it - - _ T ----- June 22 1970 L ' f ' ANALYSIS OF ALTERNATIVE ABM LIMITATIONS IN SALT The advantages and disadvantages of various ABM limitations are considered from the US point of view These include a National Command Authority NCA defense of Washington a defense of several Minutemen wings a freeze of the present Moscow system either with no improvements allowed or with no limitation to its upgrading and finally a zero ABM level on both sides The preferences to which these considerations lead are then set forth I ABM for Washington Although many configurations are possible we assume an allowed system would consist approxima t ely of two PAR faces two MSR's and 100 Spartan and Sprint interceptors Advantages to the United States I 1 ''A defense of Washington would limit blackmail by a small nuclear power This argument cannot be given much weight since the number of significant U S targets 1s so great that blackmail effectiveness is not much different with or without Washington being protected 2 A defense of Washington would offer at least some protection again t a nuclear accident This is true only it the accidentally launched mi ssile is targeted for Washington and is not heavily decoyed Considering the likely size of the target list in the Soviet SIOP the probability on an accidentally launched missile being directed against Washington is rather small However if Wahington does become protected by an ABM system the number of Soviet missiles targGtcd on Washinr ton will probably be substantially increased and therefore the probability of an accidental launch on Washington would be increased Clearly thi s increase might offset the protection that the AHM would provide but a definite a s sessment cannot be made 3 wA defense of Wahington would give us a few additional minutes for deeision-making during an initial attack period Unfortunately thee ffectivenes s of th e A I 3M a a inst a Soviet attack is not sufficiently high to insure even a few additional minutes of protection so far as our planning goes CLASSIFIED ' uj'Jcr v e o ' _' 2 ByLC V'_NA ¼ Da1 June 22 1970 ' •---·-----· ·---· Moreover our plans will have to assume that the Soviets if they so desire can completely overwhelm the NCA ABM and not permit any additional survival time by inc eased t rgeting and salvo size on Washington CNar additional targeting on Moscow as a result of their ABM deployment may serve as a guide to their reciprocal action 4 A deployed ABM defense will provide us with i portant production and deployment experience which would be significant in case of treaty abrogation This benefit would only occur if at a later date we expanded nr ABM by producing and de loying the very same system and components Once a system c£ this complexity is deployed flexibility is lo t One cannot test a deployed system in most of the ways that testing can be done on Rand D ranges By maintaining ·an active R aRd D effort and field testing we would b gaining more meaningful experience with BMD technology and would be better prepared to shift to a more modern system if deployment were required a t a later date 5 A limited ABM defense system would provide a base for expansion if the treaty were abrogated This option would buy a small amount of lead time if we should ever want to go to a full system of the sawe design Hut the longer the period that passes the less likely that an enlarged system would be compatible with the old one Thus the bead start this provides is small and vanishes with time 6 Even a geographically limited ABM defense would provide some damage limitation in the case of a nuclPar attack especially if the agreement limited the total size of the opponents• offensive force as well The extent of possible damage limitat i on is seen to be very small indeed when it is recognized that with a fixed force of roughly current size the Soviet Union could by re-targeting and upgrading their force readily overcome the small protection that a NCA AMB defense would provide At best the HMD would neutralize 10-50 of the Soviet warheads which may exceed 2 000 Disadvantages to the United States of NCA ABM Deployment 1 The cost would be difficult to justify · particularly in a time of tight military budgets Tais cost would appToximate that of Safeguard Phase I $4 5 billion plus development and fabric tion of warheads for the interceptors There would be con iderable political complications for hoth Congress and the Administration in arguing that the defense if it was workable should be limited to Washington only while the Soviet Union's corresponding defense would be centered on ibs most populous region DiCLASSIFIED ' uj' r v e · 0 2 ' 'it ByLCv'_ AR 4 Da - June 22 1970 ·•-------------·-··--· J An NCA HMD deployment would open the question of defining equivalence of the U S and the S U systems Equivalence assessments are very difficult to make because a Different geographies threat corridors and radar coverage are involved for each NCA b Different technology is utili7 ed in each of the two systems It is unlikely that agreement could be rea hed on the relative effectiveness of American and Soviet radars interceptors warheads etc c The effective threat to each of the NCAs is different d The value of Moscow's NCA can be assessed as being different from that of Washin ton's since it is the Soviets' largest population center as well 4 As a consequ nce of the difficulty of defining equivalence for the Moscow and Washington BMD's we may find ourselves in an escalating Face with the Soviet Union even if defense is limited to the NCAs Our initial BMD would be of a later technological vintage and have wider coverage than the present Soviet system This in turn may force the Soviet Union to build a newer system which would include 360° coverage higher # frequency and more agile radars as well as higher performance and larger numbers of interceptors Developmn c ts in this direction would raise suspicion here that such moves were upgrading their air defense system to an ABM capability The net result would bet destabilize the arms limitation agreement that had been reached Thus it appears that the advantages claimed for NCA AHM defense diminish and in some cases vanish upon inspection and in any event the residual advantage aecrues to the Soviet Union as well in some cases proportionately more The disadv ntages appear substantial and may substantially prolong the time needed to reach agreement and threaten the durability of an agrement if reached II ABM Defense for Minutemen In view of the disadvantages of an NCA AllM defense it is useful to ask if the U S might not be better off if it could negotiate aru 1 ABM defense of Qme Minutemen such as Safeguard Phase I toward which it is now working in place of an NCA RMD We list the anvnntages that might be claimed and our assessment of them 1 Safeguard Phase I would provide us with production and employment experience as well as a base for expansion in the case of treaty abrogation DiCLASSIFIED Au hcr € 2 ' fil ByLC V l APl Da Mt -4- June 22 1970 ' •---·- ----· ·--· The severe limitations described under points 4 and 5 of the Advanta cs Part I of an CA BMD apply equally here 2 Sa Ceguard Phase I would strengthen our deterrent by protecting a part of our retaliatory force 'l'his claim would have force only if the Soviet planners of a counterforce strike would 'not compensate by retargeting more of their missiles on our defend ed missiles How many of their missiles might be expended in overwhelming such a system is estimated differently by various analysts but it is in any cnse a small fraction of the 100 interceptors that would be allowed Even with perfect o peration of the BMD s ystem it could not be as high as 100 because some of the Sprints will defend MSUs Moreover one can expect preferential targeting ag inst the radars so that they would probably be destroyed before all the interceptors were fired But more damaging to the expectations of significant protection by an equivalent of Safeguard Phase I is the inherrent vulnerability of a mall ABM system to a large salvo of iocoming missiles Even the most pp'tlimistic proponents of Safeguard have argued that Phase 1 makes no sense alone it cannot now be claimed to significantly strengthen our deterrent 3 Safeguard Phase I can be quickly thickened by the addition of more interceptors in case of a real threat to the U S deterrent should develop This claim distorts the real situatinn in three ways by implying that our esponse to a threat to our deterrent should be a thickening that this can be done ''quickly and that such a threat can develop so fast that other countermeasures would be t6o slow It has been demonstrate4 that thickening of Phase I is much less cost-effective than developing a system dedicated exclusively to the protection of Minutemen It is extremely unlikely that a threat to our deterrent will develo suddenly If it should there are specific measures that could he taken Much more likely however is a gradual erosion of some part For this eventuality there is a wide spectrum of alternative that can be developed and deployed on the same time scale as thi kening could be accomplished These include superhard silos more Minutemen ULMS and improved penetration capability for SAC III Var ous ABM Defense Levels for Moscow The Current Moscow System with No Improvements 1 At present the Moscow Dog Houses and the similar Chekhov installation still do noi cover all of the US SLBM D-iCLASSIFIED Au h r y IE ··--- l'L'l f _ _______ ByLCll h'AM Oat _5 - June 22 1970 threat co ridors · so that the system remains vulnerable to penetration as well as to exhaustion 2 Althougb the Dog House at 400 MHz is much more capable tha the lower frequency Hen House it is not tecl nically equivalent to the PAR or the MSR · It is vulnerable to nuclear effects and although it is part of a defensive system ii is much softer than P and MSR With no hand-over capability vith great physical vulnerability and susceptibiJity to refraction errors and to blackout it is not suitable for supporting SAM upgrading 3 Despite the U S retargeting reaction to this system its effects on the U S assured destruction capability can easily be accommodated by our presen foree or any fraction of it that might emain after agreed upon reductions 4 Nevertheless if the Moscow system is allowed to remain there will be suspicion that more interceptors can be added quickly that the system components can be clandestinely upgraded and that the sy tem can be internetted with $AMs to provide some ABM capability This may result in our decidi ng to allocate a significnntly larger fraction of our strategic force to counter Soviet defenses The Current Moscow System with no Limit on Upgrading 1 Permission to upgrade would probably lead to theerectioa of more radar faces covering all threat corridors and to the deployment of new Soviet radars and interceptors which match or exceed the capability of the MSR the Spartan and the Sprint interceptors 2 A substantially upgraded Moscow system may extend the area of d efcnse coverage and provide a ruuch better defense of the radars thereby requiring a larger committment of our strategic force J Kxpansioo of the area covered 1 nd an upgrading of the technology of the Moscow system would provide a permanent ra ti onale for suspicion of SAM upgrading such that the treaty itself woulrl brundermined A Zero Level A BM for both Sides 1 Such an agreement would eliminate the fear of upgrading either of the local effectiveness of the Moscow system or of its providing their air defense with an ABM capability As imp ied above this would remove the most persistant pre sure for continuiog a -t chnologica l a ms race w thin • the framework of an agreement that keeps some ABM deployment V DECLASSIFIED w 1cr t E • 0 12-f 'ii_ _ ByLCV AR Da c fd • ' •--------· ·---- 6- June 22 1970 2 A zero-level ABM agreement would eliminate all problems of determining equivalent capability or equivalent levels in two differen t NCA BMD systems and may therefore accelerate the negotiation of an agreement 3 By reducing the targeting required for the Moscow area and in reaction to a Eossible SAM pgrade such an agreement would minimize the size of our req uired retaliatory force This could lead to a corresponding reduction in costs and would facilitate possible future a reements on force reductions on both sides 4 A zero ABM agreement would lower U S defense costs by avoiding an investment in an NCA ABM and the adnitional co ts of countering a Soviet NCA ABM Moreover we gain some advHntage here in that a greater Soviet investment in deployment has already been made 5 Such an agreement woulrl confirm a mutual committment to a deterrent strategy There would be a psychologi al gain by indicating in this way that the Soviet Union is abandoning any pretense that Moscow is defended and that deterrence was its accepted policy 6 A zero level ABM agreement would the Soviets to upgrape their air defense view of defense would not justify costly at tightening air defense in the absence reduee pressure on since a balanced measures aimed of BMD 7 Such an agreement would set a precedent for dismantling and suspending the deve l opment of lar e strategic systems This would in turn win approval of the many nations who are looking for a Soviet- US action of some magnitude in responce to their committment in the Nuclear Non-proliferation Treaty and it would create a favorable atmosphere for further arms control agreements as well as a reasonable amount of time in vhich to work them out IV Conclusions Oi t the basis of these considerations we conclude that the most beneficial agreement we can reach ·with the Soviets is one tb t prohibt°s all ABM systems including the current Moscow system Such an agreement would be the least costly the least complex the most stable amd probably the most quickly negotiated of all the altern tives we have considered If the Soviets will not agree to dismantling the present Moscow system our recommendation would be to limit it to the components we alrcadv see 1 Dog House Checkov and 64 launchers With the Soviet ABM limited in this way we conclude th the costs tons of proceeding with any BMD of our own considerably exceeds the benefits Consequently in our -7- June 22 1970 view the U S should be willing to accept a freeze on further BMD deployment -- the Soviets keep what they have and we stay at zero Perhaps this concession can find some compensation elsevhere in the negotiations If neither of thes e positions can be agreed upon and a J••ited regional deployment of ABM systems is seen to be mutually desirable we would recommend a NCA defense rather in than a limited defense of Minutemen An agreement which geogra hically limits the BMD on both sides b 11 -t inc ud s very little or no limitation on improving or upgrading opens a Pandor 's box of complications It should be accepted only as a last resort ---000--APPENDIX on the Problem of Early Warning Irrespective of whether the NCA 0ption or the Zero ABM option is adopted we have to fa ce the basic asymmetries that exist between the Soviet Union and the U S in relation to radar early warning The U S has three BMEW stations and seven radars to provide early warning against SLBM's The U S is planning to phase out two of the BMEW stations in about two years It is the U S intention to depend on satellite early warning and over the horizon radar in the future IQ the Soviet Union we think that the Hen House system serves the multiple role of early warning space track and R D The present NSDM requires that those Hen House radars facing U S attack corridors be dismantlei There exists some difference among the agencies as to which installations are covered by this directive but some certainly are We consider the r quirement to dismantle these Hen House insiati tion will be difficult to negotiate and difficult to justify The Hen Houses are undefended and extremely vulnerable to both physical attack and blacko-u b We do not see ho t ey can have any substantial capability in connection with the SA upgrade problem Requiring that the Hen Houses not be d e fenged directly would give ample protection against a conc iv bl ABM role Considering the other uses for which they may ' be needed in the Soviet Union we would recommend that they be iermitted to remain in an undefended mode P Doty R Garwin W K H Panofsky J Ruina S D Drell did not participate in t his report because he was out of the country ' - · · • · •