NATIONAL INTELLIGENCE ESTIMATE
PROBABLE WARNING OF SOVIET ATTACK ON THE US THROUGH
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nrBECTOH OF CENTRAL INTELLIGENCE Tht foilcntlna organizations participatedr preparation ot thu estimate: The Central intelligence Agency; the inteUt-genee organizations of the Departments of State, the Army, the Navy, the AW Force, ant Tha Joint Staff; and The National Security Agency. Concurred tn by the INTELLIGENCE ADVISORT COMMITTEE
ononcurring were the Special Assistant, Intelligence, Department of State, the Assistant Chief of. Department of the Army; the Direcior of Naealthe Director Of Intelligence, USAF. the Deputg Director for Inltmgenct. The Joint Staff, the Atomic EnergyBcprescntatxzc to the IAC. The Assistant to the Director, Federal Bureau of Investigation, abttalned. the subject being outside of Us furUdsetton.
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ASSISTANT DIRECTOR ONE
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CEMTIIAX INTELLIGENCE AGENCY
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PROBABLE WARNING OF SOVIET ATTACK ON THE US THROUGH
To estimate the probable degree of advance warning that could be provided by intelligence in the event of Soviet attacks on the United States and key USoverseas through
INTRODUCTORY NOTENATURE OF WARNING
When discussing the advance warning of Soviet attack which intelligence may be able to provide, it is necessary to define various possible kinds of warning:
t. Warning of the increased likelihood of war, probably resulting either fromactions or Soviet reactions to Western actions, but not necessarily involving any direct military aspect;
of increasing Soviet military readiness to attack, but withoutevidence of intent to attack or of the time of attack;
Warning of clear intent to attack;
Warning of clear intent to attack at orarticular time.
It now seems improbable thatr possibly evenould be reachedexcept in the event of high level penetration of the Soviet command, which today seems unlikely, or in case of some exceptional intelligence bonus orWhile intelligence might be able to say that the USSR would be fullyto attack within, sayays, it would find it very difficult to say whether such preparationsirm intent to attack, were primarily in anticipation of an expected US attack,eception maneuver, or were to prepare against anyWhen we speak of degree of warning, therefore, it is important to bear in mind that both time and specificity are involved, and that the earlier the warning the less specific it is likely to be. This inverse relation between time and specificity is an inherent limitation of the warning function.
'Since the Soviet attack on Uie US would be tantamount lo general war, thi* eitlmate also deals with Uie over-alt warning which the US would be likely to receive ot Soviet InltlaUon of general war it does noi consider the warning likely to be given by US or Allied early-warning radar.
The fact that warning is likely to be in some degree imprecise or.contingent also gives increased importance to other considerations affecting the warning function. The degree of warning which can be obtained will always be dependent on manyfactors, some of them unique to any given set of circumstances. Warning will depend first of all on maximum alertnessaximum scale of continuous effort by intelligence. These would probably be maintained onlyeriod of risingand might be reduced, even unwittingly, if the tension ceased to rise, if there were intermittent periods of apparently declining danger, or if Intelligence hadgiven false warnings. The effectiveness of warning also depends on thecredibility of intelligence warnings to responsible officials, for warning as ais complete only when it is acted upon. The warning process is Thus affected by the whole context of events in which it operates, including psychological factors and even pure chance. It cannot be regardedechanical process which it is possible for intelligence to set up once and for all and which thereafter operates automatically.
believeoviet initiation of general war by attacks on the US, its allies, or key overseas installations would almost certainly be preceded bypolitical tension. While suchwould in itself constitute warning that war was becoming more likely, the indications of Soviet preparations which would probably be obtained could beas evidence of preparations for defense or as partar of nerves. Therefore, Soviet behavioreriod of heightened political tension would not necessarily give specific warning of aintention to attack. Nevertheless, intelligence could probably give warning of thc USSR's increasing war readiness and could probably chart the trenda period of maximum danger.
If the USSR chose to initiate war with full-scale land, naval, and air attackseriod of mobilization, there would be numerous indications of military, as well as of economic and political measures necessary to prepare such attacks. We believe that US intelligence might be able toeneralized degree of warning as
long as four or possibly even six months prioray, and that the utfnimum period would not be less thanays.0 the number of indications would probably be reduced due to Soviet security measures, although the latter would themselves provide warning.nd, there would probably be certain indications of last-minute preparations, although processing theseimely basis would probably be difficult. As the lime of attack drew near, indications of its approach would become increasingly specific, Based on observed Soviet military activities,could probably be givenew hoursew days in advance of thelaunching of the attack.
n order to gain some degree ofthc USSR might choose to initiate general war by attacks of less than full scale, for example, by an attack onEurope with the forces currentlyin East Germany, whileattacking the US and key overseas installations. Even so, the minimum preparations which the USSR would have
to take lo assemble its forces in Eastin forward positions, to put themtate of readiness to attack, and to provide support after the attack began would probably require aboutays. Wc believe that warning of the probability of attack could be given about one week in advance, but the period might varyew hours to as much asays, depending on the seasonal pattern ofmilitary activity.
If the USSR chose to undertake aair attack on theong-range aircraft which we estimated tn4 could be launched for such an attackprior preparations would beWc believe that the indicators would probablyeaningful pattern in time for intelligence to giveays prior to attack.
We have estimated inhat the bases in the Kola, Chukotski, and Kamchatka areas have the capacity ofircraftc do not believe that they arecapable of doing so at short notice. Accordingly, we believe it virtuallythat an attack of this scale launched against the US4 couldigh degree of surprise. Ascale of atlack0might, however,ighof surprise even
7 the bases, training, andof the Soviet Long-Range Air Force
AsMilanl Chief oi. and lhe Dliee-loc ol Naval Intelligence dUsenied from thil judgment inn thc ground thai Intelligence Ii Insufficient toinite estimate ot the number of aircraft which could be launched, (or thc full text of the dissent, seearagraph
could,ajor effort; be improvedoint where only minimum preparations would be required in advance of aattackircraft. In this case, the period of warning might beto the time required for the staging operation at the Chukotski, Kamchatka, and Kola bases. Intelligence might be able to discover the movement of aircraft to the staging bases, and if thiswas in fact discovered, we believe that warning could be given at leastours before thc attacking aircraft reached the early warning radar screen. However, if this movement was notwarning of attack could be given only if continuous reconnaissance of the staging areas was being carried out. Inase, the period of warning might be reducedew hours, or evento zero, because of probableand delays in processing andthe results of the reconnaissance.
here are two possible ways in which the USSR might7 (and possibly somewhat beforelaunch an attack on the US inay that no specific warning would be likely before the actual launching of the attack:
a. Assuming that the USSR pressed ahead with development of its advance bases in the Chukotski, Kamchatka, and Kola areas, and with thc generalof its Long-Range Airnormal" pattern of activity involving these bases would tend to be established. Under these circumstances, anumber of aircraft would almostbe able to take off from these bases (and from Leningrad)urpriseupon the US without any suchprior preparations or assembly as-
would particularly attract the attention of Allied intelligence.
ssuming that the USSR acquires an Inflight refueling capability (which it can do although there is no evidence atthat the Soviet Air Force is practicing this technique) and develops it to thedegree. Soviet long-range bombers could be launched from home bases and, without staging at advanced bases, refuel from tanker aircraft in order to attain the necessary range for attacks upon the US. We have estimated inhat thc USSR could haveanker aircraft inhus, eventhat some mission aircrafl from the nearer home bases such as Leningradno refueling, the scale of such an attack would probably be substantially less than the maximum.
f the USSR, concurrently with any of the scales of attack discussed above,offensive submarine operations against the US and key overseasit would be necessary for thefleet to proceed to wartime patrol stations shortly before the expected com-
mencement of hostilities: The passage of these submarines, if detected, wouldup to two weeks warning of Soviet preparation for attack against the US and key overseas installations.
oviet preparations to receive ablow from Allied air-power would probably provide some Indicators of Soviet attack. Minimum preparations would probably include the alerting of air defense forces and thc civil defense organization, preparations of military units and installations (or air defense, the dispatching of submarines to locate US carrier forces, the evacuation of keyor even considerable segments of population from potential target areas, and some measures to increase Soviet ability to recuperate from nuclear blows If these steps were taken, they would probablyarning period of as mucheek toays, and, taken in conjunction with other indicators, would greatly increase the deflniteness of any warning US intelligence might be able to give.
WARNING FROM SOVIET BEHAVIOR IN VARIOUS CIRCUMSTANCES
he various possible circumstances in which the USSR might decide to attack the US and enter upon general war wouldonsiderable bearing on the degree ofwhich might be obtained.
a. There are three situation! ln which Uie USSR might decide lo attack lhe US and key overseas-installations, thus initiating genera) war. These situations would arise if theleaders came to) that the USSR had acquired such military capabilities that ll could be certain of successeneral war;
hat an attack by the US and its allies on thc USSR was imminent and lhat Uie USSR's only hope of survival lay in seizinghat an Irreversible shift in Uie relative weight of military power waswhich would ultimately force the USSR to choose between certain defeat in war and sacrifice of ils vital Interests. We believe that Uie Soviet leaders are unlikely to come to any of these conclusions during the period of this estimate.
b. Thereossibility that general war might occureries of actions and counteractions in some local crisis which neither tlieU&SH nor thc Western Allies ong-
Inally intended to lead to general war. It the USSR believed that the issues at stake were vital to its security or that thc loss of prestige involved in backing down would be equally dangerous to Soviet power, and if It believed that the US would not concede, then the USSR might decide that general war was theconsequence of the crisis and that It should seize the initiative. We believe that tf the USSR decides to launch general war in thc period throughhc decision is most likely to come as the consequence ofituation.
Likelihooderiod of Tension. In the situation described under b.oviet decision to attack the US would be precedederiod of heightened tension. Moreover, even if the Soviet leaders reached any one of the three conclusions in a. above, they would probably do so because of an important shift In International alignments, or because of some equally open and marked alteration, or impending alteration, or the relative weight of military power. Such developments would themselves be likely to produce heightened political tension. There are situations,inoviet decision lor war could be taken In the absence of political tension. Foroviet decision motivated as underbove might be the result of some technical advance In Soviet militaryunknown to the Western allies, or adecision motivated as underbove might be the result of some secret technical advance in Weslern military capabilities of which Soviet intelligence learned. Wethat such situations are unlikely lo arise Therefore, since an atLack on the US, If It occurs, is most likely to be the result of the situation described innd would in that case inevitably be precedederiod of heightened tension, we concludeoviet attack on the US and keyinstallations would almost certainly be precedederiod of heightened tension.
Reliability of Political Indicatorseriod of Tension While the existencerior period of tension would in itselfwarning that war was becoming more
likely, it would also greatly increase theof obtaining from Soviet political bc-
pecific warning of attack. Most of the political actions taken by the USSRa period of war preparation might not differ greatly from those undertakentandard routine ln any period of heightened political tension. These actions mightdiplomatic approaches to some states designed to Influence them towardof their alliances wiUi'Uie US, massive "peace" propaganda directed at theof Weslern states and intended lothe will to resistor to destroy conB-dence In the motives and Intentions ofexplicit threats against would-be aggressors; new proposals to ban nuclear weapons; instructions to Communist parties to ready themselves for their sabotage and subversion missions in the event of war;propaganda directed to the Bloclo prepare them psychologically for "resistance iail such actions, however, could be interpreted as defensively motivated or as partar of nerves. Thus while they might provide warning of thelikelihood of genera) war. they would not provide specific warning of attack.
Reliability of Military Indicatorseriod of Tension. The existenceeriod of. heightened political tension would also make more difficult the determination from Soviet military preparationspecificto attack. If Ineriod the USSR undertook various military preparations. It would probably be as difficult to distinguish offensive from defensive intent as in the case of indicators from Soviet political behavior.rotracted situation of this sortprobably could only give warning of the USSR's increasing war readiness and chart the trend toward the period of maximumbut not warnoviet Intention lo attack. The USSR might carry through these preparations not In order to Initiate war but in readiness for instant retaliationS attack which it feared was Impending.
Possibility of Soviet Deception. It would also be possible for the Soviet leaders,eriod of prolonged tension in which they had brought both their political and militaryto an advanced stage, lo bring aboul an amelioration of the crisis atmosphere as a
deception move. They could oner concessionsails for new negotiations, nnd simulate reduction of some of their militaryor even actually reduce them. If they considered surprise essential lo their strategic plans and believed that they still could achieve some degree of surprise in their Initial altack. this wouldikely course for the Soviet leaders to pursue. However,ourse would involve sacrifice of some ImportantAn initial surprise assault aimed at Western retaliatory power wouldave to Include air attacks on the territories of some stales which the USSR mighthave had some hope of being able to neutralize politically. It would also involve the clear assumption of responsibility forwar by aggressive action, and thus might harden the will to resist In Western countries. However, the Soviet leaders would probably accept these disadvantages anddeceptive political maneuvers if they considered that lhe maximum degree ofattainable was essential to theirplans.
arge degree of deception could be Introduced into Soviet behavior. Allied intelligence might still be able .to detect the continuation of specific miliiarySuch indications could be Interpreted as due to Soviet caution and mistrust, but they would also point to the possibility of amaneuver and they would be particularly significant as evidenceoviet Intention to achieve surprise in launching general war.
Summary. We believe, therefore, that Soviet behavioreriod of heightened polilical tension would not necessarily give warning of atlack. It would establish that the likelihood of general war was Increasing and probably that Soviet readiness forwar was also increasing. It would also lead to heightened activity and sensitivity on the part of Allied Intelligence. However,elligerent and unyielding attitudeefensive and conciliatory one wouldure guide to Soviet intentions
II. WARNING CW FULl-SCAlE SOVIET ATTACK
course open to the USSK would bentlnck on thc US and simultane-
ously on slates allied with the US, undertakeneriod of mobilization.lan of atlack would sacrifice strategic surprise in favor of maximum military preparation,the USSR might still hope to achieve some degree of tactical surprise.
hc range of activities necessary for such full mobilization of war potentialighly industrialized state like the us.sk ts soand involves so many measures affect-ing broad sections of the population thatotalitarian government would find itto conceal all of them. Inomplex redirection andof productive effort would have to take place as materials, manpower, andwere transferred from consumption and Investment goods industries to armament These measures would probably be impossible without thc use of publicmedia. Manipulation of domesticis soreoccupation of the Soviet Government and Its concern overmorale under conditions of crisis is so intense lhat its vast propaganda apparatus would certainly be openly committed tothe Soviet people to withstand the strains of general war. In the military field itself, the induction of additional miliiary classes, formation of new units and fleshing-out of existing units to full strength,and more realistic training, redeployment of combat groups to forward areas inariety of logistic measures would hardly escape entirely the observation of Western intelligence. In particular. It would be difficult to avoid detection of large-scale troop movements In East Oermany. Specific preparations which if detected would give warning of attack on thc US would arise from the activities of the Soviet Long-Range Air Force. These arc discussed inelow.
e believe that we would be most likely to receive numerous indications of large-scale Soviet mobilization in lhe period from about six months to about one monthay. largely because the preparations likely to be undertaken up to this lime would be those least susceptible of concealment. From0 to0 days, however.
would be likely lo get much less In the way of indications because the preparations In this period would be those which Soviet security Is best equipped to conceal.by about one monthay the progressive tightening of Soviet securitywould probably haveigh point. There would almost certainly be ain information from sources within the Bloc; at the same lime, however, theup of Internal Bloc sources because ofsecurity measures would In Itselfan indication of Soviet preparations. Then. In the period0 andn, we could expect Indications of last-minute preparations. At this time, however, there woulderious problem of processing such Indicationsufficiently timely basis.
e believe that Western intelligence would probably be able to sort the variety of indicatorseaningful pattern al aearly stage of Soviet mobilizationull-scale altack. US Intelligence mightaware of this mobilization as long as four or possibly even six months prioray. The minimum period would probably not be less thanays. Even thoughwas able to giveeneralized degree of warning, showing the progressive Increase of Soviet war readiness. It would probably still be able to chart the trend of full-scale preparations, to anticipate their probable course to completion, and thus to designate the beginningeriod ofdanger. It might even be able tofeatures of Soviet full-scale mobilization which because of their uniqueness or extreme costliness could be interpreted specifically as evidence of an intention tos the time of atlack drew near.of Its approach would becomespecific Based on observed Sovietactivities, warning could probably be givenew hoursew days inof the actual launching of thc attack. This would be rendered very difficult, however, if Soviet forces, when their preparations for attack were known to be near completion, undertook air. naval, and groundor attempted major feints. These activities might provide evidence of Soviet In-
tention to attack, but would aggravate the difficulty of determining the lime of such attack. It must also be recognized that, in theory at least, the USSR could alwaysfrom or delay attacking even after preparations were complete. Hence theof miliiary readiness, taken bywould noi necessarily provideevidence lhat attack was certain.
III. PHOBABIE DEGREES OF WARNING IN THE EVENT OF LESS THAN FUfl-SCALEven if the USSR attempted to achieve the utmost surprise in Initiating general war and accepted all feasible!imitations on its prior preparations, it would still probablyinimum number of prioratter of necessity and elementary prudence In order to beosition lo wage general war. At least some of the generaldiscussed in Section II above would almosi certainly have to be undertaken, evenigh degree of prior mobilization was foregone. Some of these preparations would be detected by Allied Intelligence, but it might be very difficult lo ascertain any such clear pattern of preparations as would be discernible in event of mobilization for full-scale attack. Consequently, we believe it possible, though unlikely, that thesewould not leadarning of attack, especially if they were carried outong period of time and with carefulf the USSR attacked the US and key overseas installations without full priorfor general war. and hence without full-scale attacks in other areas, two general alternatives would be open:
USSR could combine Itsthe US and key overseasa ground campaign chiefly inwithout prior reinforcement ofin East Germany.1
USSR could undertake initiallypossibly other forms of attack, against
USSRcou'd ot course strengthenund attack by some degree of prior reinforcement. For the purpose of thit eitlmate. however, we take the above cat* as the llmlUnc one le. an* prloi reinforcement would tend to provideindicator! and hence additional warnlne.
thc US and key overseas installations, but delay Its ground campaigns and discernible preparations for other military operations until alter these Initial attacks.
Soviet Campaign in Western Europe ond Simultaneous Attacks on Ihe US and Key Overseas Installations
f the USSR chose to Initiate general war by an Attack on Weslern Europe with the forces currently stationed In East Germany and the Satellites, together with attacks on the US and key overseas installations, the degree of its over-all war preparations before such attacks would vary greatly depending on the Intensity and duration of the political tensions which preceded the attack. If, as we think likely, there hadong period of crisis, the USSR might have alreadyonsiderable degree of military andmobilization lor war. and Its foreign and domestic political preparation might be well advanced. Therefore, as we have noted, the indicators derived from this range of activities, though warning of the Increased likelihood of war, would probably be ofsignificance for warning of this type of atuck.
ven so. the local preparations which the USSR would still have to takeinimum for an attack with forces stationed in East Germany would provide some degree of Some time would be required tomajor elements In forward positions, although this would vary seasonally. (The longest period required would be between May and August when units are split between home stations nnd field training areas; aperiod would be required betweenand March when units are consolidated al home stations; the minimum periodwould be in April when units areto training areas and inwhen units are either engaged In large-scale maneuvers or are being moved back Lo home stations) Olher minimumwould include the release from stocks of. transport, munitions, and supplies inwell in excess of those used even on full-scate maneuvers. In addition, some two
weeks before the attack it would probably be necessary to begin the movement of large numbers of locomotives and rolling stock from East Germany to the Soviel border ln order to prepare for resupply and reinforcement operations to support and expand the Altogether, the USSR would probably be engaged in these preparationseriod of aboutays and US Intelligence would probably begin to acquire some Indicators at an early stage, although jrarying with the season of the year. We believe that warning of the probability of atiack could be given about one week in advance. However, ln the absence ol other indicators and with Soviet actions appearing lo be partormalthe warning could vary as follows:
ew hoursew days in April and in September-October;
from two to five days in the period November-March;
from five toays In the period May-August.
the USSR undertook concurrentsive submarine operations against the US and
key overseas installations. It would befor the submarine fleet to proceed to wartime patrol stations shortly before thecommencement of hostilities. The passage of these submarines, if detected, would support up to two weeks warning of Soviet preparation for attack against the US and key overseas installations.
extent to which the preparationson simultaneously for air attack onand key overseas Installations wouldconfirm and/or advance the warningsomewhat upon the planned scaleattacks, as discussed below.
Initial Attacks on the US and Key Overseas Installations
the purposes of this estimate itnecessary to consider two types ofon the US and keyaximum effort using asas possible: (b) an attack designeda high degree of surprise. Theundertake these air attacks on thekey overseas installations simultaneously
ull-scale attack or with the ground campaign and submarine operations discussed in. Alternatively, the USSR could initiate general war with such aironly, while delaying discerniblelot other military operations In order lo increase the likelihood of surprise against the US. In this case, the very disparity between preparations for long-range air operations and those for other general warighly significant Indicator of the probable nature of the Initial Soviet atlack.
aximum Scale Attack. We haveInM that by exercising its maximum capability the USSR could nowong-range aircraft against the US in an Initial attack and that7 this number could be Increasedprior preparations would be required, particularly in the early part of the period covered by this estimate. These wouldImproving airfields, maintenance and fuel storage facilities in the Chukotski,and Kola areas, bringing personnel and equipment to full strength in long-range air units, intensified training of air personnel, increased frequency of long-distance training missions, and raising levels of maintenance.
t present such activities would require at least several months and would probablyknown to US Intelligence, especially if carried forward with great urgency. Throughout the period of this estimate the critical Indicators would be those relating to increased levels of activity at staging bases in the Chukotski, Kamchatka, and Kola areas. We believe that the indicators would probablyeaningful pattern in time fortoeneralized degreeays prior to attack. On the olher hand, such preparations could be undertaken gradually over the next few years. 7 the bases, training, and equipment of the Soviel long-Range Air Force couldoint where only minimumwould be required in advance of an atlack For example, il might not then be
The warning problem would probably not be sie;-mficantly different If some portion of thesewere tankers.
necessary to undertake such finalas the movement of personnel andor these preparations might be oneduced scale that they might not be Under these circumstances,of the preparations taking place in Ihc Soviet Long-Range Air Force might be few, and warning of air atlack would dependentirely on indicators received during the staging of aircraft through advancedn thc course of the staging process Allied Intelligence might be able to discover the movement of aircraft to the staging bases. If this movement was in fact discovered, weUiat4 warning could be given at leastours before the attacking aircraft reached the early warning radar screen. ncreased handling capability at staging bases and reduction of flight time by increased speeds of Jet aircraft might decrease thederived from discovery of movement ofto staging basesinimum of aboutours before attacking aircraft reached the early warning radar screen. However, if this movement was not discovered, warning ofcould be given only If continuousof the staging areas was being carried out Inase, the period of warning might be reducedew hours, or even virtually to zero, because of probable difficulties nnd delays ln processing andlhe results of thef US overseas Installations were to be attacked simultaneously, the additionalwhich would be necessary would not add significantly to the risks of detection. Tlie long-rnnge air arm would already beaximum condition of readiness and the readying of theight bomber units which would be used for attacks on USIn Western Europe, the UK. and some parts of the Middle East could bewithout serious additional risk of detection. If guided missiles were employed in such attacks, no warning of their use would be obtained, apart from the generalizedwhich might have been derived from prior preparations
urprise Atlack We have estimated Inhat if the USSR attempted a
surprise attack against the USwould probably be launched frombases In the Chukotski, Kamchatka, and Kola areas. The capacity of these bases was estimated toircraft* We do nothowever, that these bases are currently ready to launch this scale of attack on short notice. Preparations would be required, which would probably be detected by Alliedand wouldeneralized degree of warning of about IS toays.we believe It virtually impossible that an attack of this scale against the US4 couldigh degree ofeduced scale of attack0might, however,igh degree of surprise even
s ts evident from paragraphsndbove, the USSR, could, provided base construction, training, and equipment of the Soviet Long-Range Air Force were sufficiently advanced, launch its maximum air attackircraft against the US under suchthat the period of warning wouldbe of the order ofours, but might be considerably less If the movement of aircraft to staging bases was not discovered. The maximum Soviet air attack could thusigh degree of surprise. Even if the USSR chose to reduce substantially the totalof aircraft, participating in the atiack, lt would still probably use the Chukotski,and Kola bases to full capacity, and therefore not greatly reduce the likelihood of discovery of aircraft moving to staging bases.
here are two possible ways in which the USSR might7 (and possiblybefore that year) launch an attack on the US Inay lhat no specific warning would be likely before the actual launching of the atiack:
a. Assuming that the USSR pressed ahead with development of its advance bases In the
'The Assistant Chief of Staff.nd thcof Naval Inlelligence dissented from this Judgment in4 on the ground that Intelligence Is insufficient toinite estimate of lhe number of aircraft which could be launched: for the full text of the dissent, see,
Chukotski, Kamchatka, and Kola areas, and with the general preparation of its Long-Range Air Force, "normal" flights of aircraft to and from these bases would almostoccur in increasing number as theol the bases progresses. attern of activity would tend to be established. Under theseonsiderable number of aircraft would almost certainly be able to take off from these bases (andurprise attack upon the USany such unusual prior preparations or assembly as would particularly attract the attention of Allied intelligence. We areto estimate the number of aircraft which might beosition to participate ln such an attack.
b. Assuming that the USSR acquires anrefueling capability (which it can do although there is no evidence at present that the Soviet Air Force Is practicing thisand develops it to the necessary degree, Soviet long-range bombers could also be launched from home bases and, withoutal advanced bases, refuel from tankerIn order to attain the necessary range for attacks upon the US. We have estimated inhat the USSR could haveanker aircraft in Thus, even assuming that some mission aircraft from the nearer home bases such as Leningrad required no refueling, the scale of such an aitack would be substantially less lhan thc maximum.
IV. WARNING FROM SOVIET PREPARATIONS
TO RECEIVE RETALIATORYn important element not Included In the foregoing examination Is that of Sovietpreparations toetaliatory blow from Allied air power. Minimumwould probably include the alerting of air defense forces and the civil defense organlration. preparations of military units and installations for air defense, theof submarines to locate US earner forces, the evacuation of key personnel or evensegments of population fromtarget areas, and some measures toSoviet ability to recuperate fromblows. If these steps were not taken.
they would constitute serious limitations on the USSR's ability toetaliatory blow. II they were taken, theyarning period of aa mucheek toays, and, taken In conjunction with other Indicators, would greatly Increase the definiteness of any warning USmight be able to give. The risk which the USSR would be willing to acceptesult of neglecting some or all of this type of defensive preparation would depend In part on the degree of success which the Soviet leaders expected their own initial attack to achieve. We believe that in elementarythey would be unwilling to forego all preparation toetaliatory blow, and some Important Indicators of this type would' probably be obtained.
V. THE PROBABLE SOVIET CHOICEUtt-SCALEURPRISE ATTACK
he Soviet choiceull-scaleor some one of the alternative scales of surprise attack would probably depend ln part on the Intensity and duration of the crisis which preceded the Soviet decision to attack. The preference shown In Sovietdoctrine for offensive action only after
maximum preparation and a_ high degree of superiority to the enemy has been achieved might argue for the postponement of decision to the last possible momentrolonged crisis might thus result during which Soviet general mobilization would be brought near to completion. This might make full-scalefeasible and would also facilitateOn the other hand, the USSR might estimate that thc process of mobilization itself, especially If It included forwardof large bodies of troops. Into thearea, wouldesternand result In the initial attack being made on rather than by the USSR.
robably the decisive argument for asurprise attack, however, would be the overwhelming importance to the USSR ot effectively blunting US retaliatory power and disrupting US mobilization. We believe lhat in the period throughhe Soviet leaders, If they decided to Initiate war, would consider some form of surprise attackto achieving their objectives, and that they would therefore give highest priority to achievementubstantial degree ofagainst the continental US and keyoverseas.
HKMCftAtmUM FOB HOLDERS OFSli SUBJECT: Correctloo
Plenne coke, the following correction In SNIB"Probable Warning of Soviet Attack on the US Throught pageineeleteubstitute "llmltationn."
CE/.TRAL IfvTELLIGEHCE AGENCYOriginal document.