Foreign Relations of the United States, 1961–1963, Volumes VII, VIII, IX, Arms Control; National Security Policy; Foreign Economic Policy, Microfiche Supplement

233. National Intelligence Estimate, NIE 11–61, April 6¹

April 6, 1961

PROBABLE INTELLIGENCE WARNING OF SOVIET ATTACK ON THE US

THE PROBLEM

To estimate the advance warning of Soviet initiation of general hostilities against the US which could be provided by intelligence, focusing on the period between the present and about 1963.

ASSUMPTION

For purposes of this estimate, it is assumed that during the period under consideration no US-Soviet agreement on arms control or system of mutual inspection will be in effect.

SCOPE

The warning of Soviet attack discussed in this paper is that which intelligence might be able to give prior to the actual launching of an attack. We do not discuss warning which might be obtained from US or allied early warning radar or other tactical detection devices, such as devices to detect ballistic missiles in flight. Nor do we discuss the possibility of obtaining chance warning from sources such as weather stations, military and commercial aircraft, or naval and commercial ships at sea whose primary mission is not warning. The possibility that the USSR might resort to an ultimatum and thus itself warn of attack in the event of a rejection is also excluded from consideration.

The warning estimate is made in the light of our current estimates on Soviet strategy and present and future Soviet military strengths, especially NIE 11–4–60, Chapter IV and Annexes. It takes into account the detailed findings of the Warning Systems Survey Committee of the United States Intelligence Board.

CONCLUSIONS

1. Direct access to the proceedings of the highest level Soviet decision-making bodies is not now available to US intelligence and may never be achieved. Hence, the warning problem is one of collecting indirect evidence, largely fragmentary in nature, and of interpreting it in order to reach judgments about the USSR’s intended course of action. Any warning given by intelligence would be the end product of a process of reasoning from incomplete evidence. It would represent a judgment of probability rather than an unequivocal warning of Soviet intent to attack.

2. If the USSR decided to attack the US, the varied preparations preceding such an attack would almost certainly include some activities susceptible of detection. The number and variety of indications obtained and recognized, and therefore the certainty with which a warning judgment could be made, would be affected by the scale and pace of Soviet preparations, the success of Soviet security measures, and many other variables—including fortuitous elements which cannot be anticipated in advance. Intelligence would evaluate these indications in relation to other concurrent Soviet activities and to the international political context within which they occurred, in an effort to determine whether the Soviet intention were to attack, to threaten, to deter, or to be ready to defend and retaliate.

3. We believe that the Soviets would feel it essential to strike a balance among the objectives of achieving surprise, delivering an attack of great weight, preparing to defend against retaliation, and preparing to recuperate and carry on the war. Many preparations and activities, especially those associated with defense and recuperation, might be detected well in advance of an attack but would be subject to considerable ambiguity as to Soviet intent and as to the timing of a possible attack. Last-minute preparations to launch an attack could permit more specific warning but would be less likely to be available in time.

4. With respect to Soviet preparations to launch intercontinental striking forces against the US, our ability to obtain warning is limited and declining:

a. At the present time, there is virtually no chance that intelligence would be able to provide advance warning of Soviet use of ground-launched ballistic missiles in an attack. Intelligence capabilities to derive warning from preparations by Soviet ballistic missile forces may improve somewhat, but given foreseeable obstacles we believe they will remain very poor.

b. If the USSR prepared to launch a massive bomber attack—involving, say, 500 heavy and medium bombers and tankers—the chances are better than even that some aspects of an operation of this size would be detected in time to provide a degree of warning before the Soviet bombers arrived at North American radar warning lines. However, intelligence could probably not provide warning if the Soviets undertook a highly secure operation to launch a reduced force of, say, 150–200 bombers and tankers.

c. The chances of obtaining warning from preparations by long range bomber forces will decline, in part because of continued improvements in Soviet security over air operations, but primarily because the growth of Soviet missile capabilities will shift the main strike role away from bombers.

d. We believe that under normal US readiness conditions and surveillance, there is some chance, although small, that a general departure into the open seas of Soviet submarine forces large enough to include all presently operational missile submarines would be detected in numbers sufficient to cause additional alert measures. There would be a fair chance that such forces approaching US coasts could be detected, perhaps a few hours or a day before the submarines reached missile launching points. A prior alert would raise the chances and increase the timeliness of any warning given.

e. US techniques for submarine detection, identification, and surveillance will probably improve, thus increasing the chances of deriving warning indications from the movements of currently-operational types of Soviet missile submarines. On the other hand, warning capabilities would be considerably less against Soviet nuclear-powered missile submarines employing 500–1,000 n.m. ballistic missiles.

5. In a period of international tension preceding a Soviet attack, intelligence might be able to give successive preliminary warnings which would have a cumulative effect. Even if such warnings contained no firm conclusion as to Soviet intentions, they could provide the basis for critical decisions regarding US political, military, and intelligence actions. The last of these might include decisions to undertake exceptional collection measures which could in turn increase the certainty of the warning judgment.

6. Considering all the factors affecting the problem of warning, we believe that in most circumstances of an actual Soviet decision to attack at present or in the near future, intelligence could give warning of increased Soviet readiness, and could infer a possible intent to attack, perhaps a few days or more before the attack. Warnings of a probable Soviet intent are likely to be given, if at all, only a few hours before attack.

7. There is little prospect over the next few years for any major improvement in the firmness or explicitness of the warnings which might be given. Improvements in intelligence techniques will be offset by a decline in the number and accessibility of dependable military indicators as missiles gain in importance and general Soviet readiness gradually rises. But unless there is a drastic change in Soviet strategic thinking or the Soviets acquire an assured capability to knock out US retaliatory forces in a single missile attack, the possibility of warning from physical preparations will not disappear. Indeed, the limited time between initial attack and potential retaliation would virtually force the Soviets to undertake various preparations, including those for defense and recuperation, prior to launching an attack.

8. In the future, however, along with indications of physical preparations, intelligence will have to place additional reliance for warning on the more ambiguous indicators not directly related to physical preparations. The international political context will assume a larger role in the warning problem. Depending on the circumstances, analysis of the political context could strengthen or impede the warning judgment. In some cases, the first preliminary warning of possible Soviet attack might arise from a judgment that the USSR was about to take a political initiative involving great risk of war with the US, or that a crisis was developing in such a way as to prompt the USSR to prepare for war.

DISCUSSION

NATURE OF THE WARNING PROBLEM

9. The ideal contribution of intelligence to the defense of the US against a Soviet attack would be the communication to US decision-making officials of clear and unequivocal warning that the USSR intended to launch an attack at a specific future time and in a particular manner, this warning to be delivered to decision-makers far enough in advance to permit them to decide upon and take effective countermeasures. To approach this ideal standard, intelligence would need to have prompt and direct access to dependable sources of information on the proceedings of the highest level Soviet decision-making bodies, or at least to their means of transmitting decisions to immediately subordinate echelons. Such access does not exist at the present time and may never be achieved.

10. In these circumstances, which have obtained throughout the period of US-Soviet confrontation, any warning given by intelligence must derive from the collection and evaluation of evidence on Soviet activities and behavior. Given the considerable effort by the USSR to prevent the collection of vital information about its military capabilities and preparations, even indirect evidence of Soviet intentions will always be incomplete. Nevertheless, were the USSR to prepare to attack the US, the varied preparations which would be undertaken would almost certainly yield discrete items of information susceptible of collection by one or more channels of intelligence acquisition. These items of information would not necessarily establish a Soviet intention to attack, inasmuch as they might also be consistent with an intention to threaten, to deter, or to be ready to defend and retaliate. Thus the warning problem becomes one of collecting indirect evidence, largely fragmentary in nature, and of interpreting it in order to reach judgments about the USSR’s intended course of action.

11. To cope with the warning problem in these terms, the intelligence community has developed over the years techniques for collecting, evaluating, and correlating indications derived from Soviet activities and behavior. This effort has included attempts to determine what general and specific preparations the USSR might make prior to initiating hostilities, to identify those preparations most susceptible to detection by intelligence, to direct collection assets towards promising sources of information, and to establish special channels for the rapid transmission and dissemination of information which may be pertinent to the warning problem. This effort is guided by the United States Intelligence Board; substantive continuity is maintained by the Watch Committee of the USIB and by its staff in the National Indications Center.

12. Through these mechanisms, a considerable capability for collecting and evaluating information has been focused on the warning problem. A fair understanding of the norms of Soviet behavior has been acquired, and a high degree of expert knowledge can now be applied to the problem of discerning apparent abnormalities which might signify Soviet preparations for war. However, because of the impossibility of predicting in advance precisely what abnormalities would become apparent should the Soviets decide to attack, warning could never be derived automatically from existing or improved mechanisms. It would always be the end product of a process of reasoning from incomplete evidence, and would therefore be a judgment of probability rather than an unequivocal warning of Soviet intent to attack.

13. Such a judgment would rest in part upon a weighing of indications of Soviet physical preparations. These indications might be found in any or all of a wide variety of categories, ranging from specific Soviet preparations to ready the long range striking forces to very generalized preparations to increase the ability of the Soviet productive base to withstand the effects of US retaliation. To date, it is in this area of physical activities that intelligence has best been able to maintain surveillance and to recognize abnormalities in Soviet behavior. Despite the capability intelligence has developed to acquire and weigh evidence of Soviet physical activity, however, any attempt to derive a warning judgment from physical preparations is subject to serious limitations.

14. Physical preparations undertaken some time before the initiation of war would offer the longest potential lead-time for warning, but in most cases only the most generalized conclusions about Soviet readiness could be drawn from them and no conclusions could be drawn as to the pace and timing of the activities. Indications of last-minute Soviet preparations would be much more significant but many of these final preparations would be undertaken so close to the launching of the attack that there would be very little time to obtain the information, to assess it, and to communicate warning to decision-making officials. Hence, the most specific warning which might be given by intelligence on the basis of Soviet physical preparations would probably be the least timely.

15. In addition to physical preparations, intelligence might acquire evidence of Soviet activities which did not in themselves increase military readiness but which the USSR might undertake prior to the initiation of hostilities. Examples are abnormally heavy censorship measures, changes in clandestine agent operations, urgent and simultaneous recall of key Soviet personnel in Western countries, and unusual restrictions on foreign nationals in the USSR. While such evidence might strengthen the warning derived from analysis of military preparations, it would not provide a convincing basis for warning in the absence of indications of increased readiness to attack. Finally, and most important, there is virtually no single preparation, activity, or combination of these which would establish conclusively that the USSR actually intended to attack.

16. In reaching a warning judgment, intelligence would evaluate physical preparations and other activities in the context of the Soviet political posture. This context has to do with the way in which the USSR is conducting its international affairs at any given time: the vigor of its challenge to the West over various issues, the apparent degree of commitment of the Soviet leaders to various positions, and the political climate in high Soviet and Bloc circles. The political context introduces more evidence but also new complications to the warning problem. Soviet foreign policy initiatives, actions, and positions are themselves often difficult to interpret. The possibility exists that interpretations of the USSR’s intentions based on its political posture would impede or confuse the attempt to arrive at a warning judgment based on physical preparations. On the other hand, analysis of the political context can serve to strengthen the warning judgment. This analysis is becoming more important to the warning process as Soviet military capabilities grow and reaction times are compressed, and as the USSR engages the West politically over a wider range of issues and geography.

17. It is evident from the foregoing considerations that any warning given would be neither complete nor unequivocal. The more indications collected and recognized by intelligence, and the more comprehensive the picture of Soviet capabilities and behavior available to intelligence, the better would be the basis for judging the Soviet course of action. But the sum of the available indications and knowledge would almost certainly be inconclusive as to Soviet intentions. Therefore, even under the most favorable circumstances, intelligence could only arrive at a judgment that the probability of Soviet attack was high. Some indication of the form, scale, or time of attack might be ascertained from the character and pace of Soviet preparations, but here too there would be uncertainty in some respects.

18. Warning can perform a useful function even where attack cannot be predicted with complete certainty. Warnings of lesser degrees of certainty may be given in such a way that they have a cumulative effect. Such successive warnings, even if they did not permit a firm conclusion that the USSR intended to attack, might still provide a basis for critically important political, military, or intelligence decisions. They might be adequate, for example, to justify undertaking diplomatic moves to cope with a developing crisis, placing US military forces at one or another stage of alert, or invoking special intelligence collection measures. Such actions might lead the USSR to change its intentions concerning attack, and this in turn would presumably produce indications which might cause intelligence to modify its previous warnings.

19. The process of warning is complete only when warnings given by intelligence are accepted as valid by decision-making elements of government. Intelligence must be able to earn credibility for its warning judgments. It must therefore make as complete as possible a showing of evidence, including consideration of possible alternative interpretations, to substantiate whatever warning is given. A warning judgment which did not carry conviction to responsible policy officials could be as much an intelligence failure as no warning at all.

VARIABLES AFFECTING THE WARNING PROBLEM

20. One of the most important variables affecting the warning problem is the international situation obtaining at the time of a Soviet decision to attack: such a decision could be taken in a period of comparative international calm or in a period of heightened international tension, perhaps occasioned by local hostilities. Other major variables, related in some degree to the level of international tension obtaining, are the level of intelligence alert prior to the initiation of the Soviet attack, the nature of the Soviet preparations, and the nature of the Soviet attack itself. These factors would have bearing not only on the chances of intelligence warning, but also on the specificity and timing of the warning which might be given.

Soviet Decision in a Period of Calm

21. It is possible to envisage a firm Soviet decision to attack the US, made at a time well in advance of the launching of the attack. A decision of this nature might be made if the Soviet leaders concluded that they had acquired a military superiority over the US so decisive as to permit them to defeat the US without receiving unacceptable damage in return, or if they concluded that the US was planning an eventual attack on the USSR and that their best chance of survival lay in attacking first. The Soviets’ assessment of the world balance of forces at present and over the next few years, as we have estimated it elsewhere, is unlikely to lead them to either of these conclusions.² However, they could conceivably reach the former if they achieved some technological breakthrough in a critical military field, and the latter if they acquired intelligence which convinced them that the US intended to attack.

22. A firm decision made well in advance would enable the USSR to take a long period to prepare, probably under conditions of maximum secrecy and possibly accompanied by large-scale efforts to deceive the US as to Soviet intentions. On the other hand, it would give the US intelligence community time to collect a broad range of indicators which might progressively assume a meaningful pattern. Initially at least, such preparations as were detected would probably not have an emergency character and would probably be regarded as a normal development of Soviet military capabilities. At some point in the course of these preparations, however, the Soviet actions might be recognized by intelligence as clearly at variance with normal patterns of activity and development of capabilities. Such recognition might stem from analysis of the preparations themselves, or from the discovery of unusual Soviet secrecy or deception attempts. This would alert intelligence and would cause it to re-examine the accumulated indicators. As the time of attack approached, actions of a last-minute character might be observed which would increase our ability to give warning.

23. We can also conceive of a Soviet decision to attack on very short notice, also in the absence of any external atmosphere of rising tensions. Such a decision might be a desperate attempt at pre-emptive attack, arising from false or misinterpreted information leading the Soviets to conclude that the US was attacking or preparing imminently to attack the USSR. While we doubt that such a circumstance would ever actually arise, we cannot exclude it.³ Nor can we completely exclude a similar short-notice decision arising from some irrationality within the top Soviet leadership. In cases of this sort, minimal Soviet preparations would ensue and the time available for their detection would be very short. The chances of warning might rest heavily on the possibility that the Soviet forces designated to carry out the attack, themselves surprised, would fail to exercise appropriate security measures. Nevertheless, if detected and correctly interpreted, last-minute Soviet preparations for a sudden attack would lead intelligence to communicate any warning judgment with a great sense of urgency.

Soviet Decision in a Period of Tension

24. Between the two situations we have just discussed, there is a wide range of considerably more likely circumstances under which a Soviet decision to attack might be taken. These involve Soviet responses to international crises and local conflicts which neither the USSR nor the US originally intended should lead to general war. The Soviet leaders might decide to attack because they believed that an actual or threatened intervention in the USSR’s sphere of vital interest could not be countered by limited means. Or they might conclude that the USSR had become engaged beyond retreat in some area where the Western Powers would be prepared to risk general war. In either case, the Soviet leaders might decide that general war and all that it involved was preferable to submitting to a serious reversal and that it would be to their military advantage to attack first.

25. In this situation the decision to attack would be accompanied by some degree of political tension, perhaps a very high degree, which could in itself give rise to preliminary warning. However, the time period over which a crisis reached an acute stage could vary considerably, and this would affect the ability of intelligence to assemble a meaningful pattern of indications. If the crisis developed over a brief period of time, and if Soviet military readiness was already advanced or if the Soviet leaders decided to attack with only minimum preparations, the indications obtained might be few. If, on the other hand, the USSR took a certain amount of time to prepare and position its forces, further and more specific warning might be obtained from the pace and nature of the Soviet preparations.

26. It is also possible that in a local crisis the USSR would decide to engage US or allied forces locally while hoping to avoid general war. This course of action would rest on a calculation that Soviet objectives could be achieved by a limited application of force and that the US would be deterred from initiating an attack on the USSR itself. There would clearly be great danger that such a situation could develop into general war. The Soviet leaders would have to recognize that the US might conclude that expansion of hostilities was inevitable and therefore itself seize the advantage of launching the first attack in a general war. Faced with this possibility, they might at some point decide to launch such an attack themselves. In the given circumstances, Soviet forces would presumably be close to full readiness and maximum security precautions would be in effect. A certain degree of intelligence and military alert in the US would also obtain. Warning of Soviet intent to expand the local conflict into a general war might be inferred from, among other indicators, those giving evidence of Soviet preparations of a scale, character, or location at variance with those required for the local engagement in progress.

27. The period of rising tension attending an international crisis or local war would in itself constitute warning of an increasing likelihood of Soviet attack, but in such a period intelligence might have its greatest difficulty in attempting to determine Soviet intentions. A period of tension would bring intelligence to a high degree of alertness and perhaps lead it to take exceptional measures to collect information about Soviet activities. In analyzing Soviet activities, intelligence would have to recognize that the USSR might be carrying out military preparations, not on the basis of a firm decision to initiate general war, but for purposes of intimidation or in order to increase its defensive readiness and its ability to retaliate should the US attack. It is also possible that Soviet preparations for war might be undertaken because of a misinterpretation of US policies and actions, by which the Soviet leaders considered that they were about to be forced into general war, against their real desire. The importance of a correct US estimate on this point would be very great, yet it would be particularly difficult to make such an estimate during a period of rising tension.

28. Analysis of the significance of the USSR’s political and propaganda activities would be very difficult. Most such activities undertaken preparatory to attack on the US might not differ greatly from those which could be expected in any period of heightened tension. Such activities could in themselves be interpreted as defensively motivated or as part of a war of nerves, and they would thus not establish that the USSR had the intention to attack. However, taken in conjunction with other kinds of indications, they might enable intelligence to give warning with a greater degree of certainty.

Level of Intelligence Alert

29. One significant effect of a period of tension as it applies to the warning problem would be the effect on the intelligence community itself. Since warning is a product of judgment, there are variable human factors which must be taken into account. Alertness would vary depending on the manner in which the crisis developed, its intensity, and duration. There are many ways in which the alertness and effectiveness of intelligence increases under crisis conditions. For example, field reporting and intelligence analysis become sharply focused on the crisis situation, new sources of information held in reserve for such situations are put into use, resources of the intelligence community are more closely integrated to deal with the crisis, and intelligence is increasingly disposed to consider whether current evidence indicates hostile intent. On the other hand, in the event of a long sustained crisis involving a high degree of tension, key personnel would be subjected to fatigue and strain. If at one stage or another apparently mistaken warning judgments had been made, undue caution might come into play.⁴

30. Once a crisis situation arises, the volume of reports increases and their reliability on the whole declines, thus confronting intelligence with a large number of ambiguous reports from inadequately identified sources of uncertain reliability. There is also an increase in the number of reports from sources of known reliability, some of which sources come into play as a result of a crisis situation. In these circumstances, communications channels may be overloaded, with resulting delays in the transmission and receipt of information. However, it is not possible for intelligence to suspend judgment until more complete and satisfactory evidence becomes available. Under the pressure of time in a developing crisis, the intelligence warnings given may be less reliable or more tentative.

31. Intelligence could employ emergency collection procedures under conditions of crisis in order to improve the quantity and quality of information available. Special reconnaissance measures could be directed against Soviet controlled territory. Agents held in reserve for such a situation could be activated. Some exceptional measures would provide information, possibly of great value, on Soviet capabilities and readiness, and inferentially perhaps on Soviet intentions to attack. Some measures in this category, in particular air penetrations, could have the effect of increasing tensions or even of precipitating Soviet attack. For intelligence to employ them would require policy decisions; these might or might not permit their use and would in any case cause delay.

Nature of Soviet Preparations and Attack

32. Because we are without access to Soviet war plans, intelligence cannot know in advance what precise preparations the Soviets would consider essential before launching an attack against the US, or what the precise form and scale of the attack would be. This means that even if intelligence had complete knowledge of all Soviet physical preparations, we could not conclude that when a particular level of readiness had been attained the Soviets considered themselves fully prepared for war; conversely, we could not say categorically that because some one type of preparation had not yet been accomplished the Soviets considered themselves unprepared. Beyond this, many specific elements bearing on the character of a Soviet attack and affecting the warning problem could not be estimated with certainty. Examples are: how much of the Soviet military establishment would be alerted prior to an attack on the US? Precisely what delivery systems would be used in what quantity in such an attack? What forces would be allocated to targets in the US as opposed to targets elsewhere? What preparation for defense and recuperation would be undertaken prior to launching an attack? Over the years, however, we have accumulated enough knowledge of Soviet thinking about military strategy to narrow somewhat the range of likely alternatives:⁵

a. First, it is clear that the Soviets regard surprise as a military factor of great importance. The USSR would therefore take extreme precautions to prevent the US from learning about a forthcoming attack. Soviet security, already tight, would be intensified and possibly augmented by strenuous attempts to deceive the US as to Soviet intentions and preparations. Many preparations might be dispensed with in the interests of achieving surprise. But in balancing the advantages of various factors, the Soviets will also take into account the great importance of delivering a significant weight of attack, preparing to defend against US retaliation, and preparing for national recuperation.

b. Second, Soviet military doctrine envisages a general war as extending beyond the first nuclear exchange, and as including subsequent major land campaigns and naval warfare. The Soviets regard broad military, economic, and human resources as important determinants in the outcome of such a war. Thus in preparation for an attack on the US, the USSR would be constrained to undertake a variety of activities, not directly related to that attack but calculated to preserve vital military and other strengths for phases subsequent to the initial nuclear exchange.

c. Finally, in planning an attack on the US the Soviets would have to consider the great variety and widespread dispersal of US and Allied nuclear delivery capabilities. They could not contemplate an attack against US territory alone, but would need also to prepare for coordinated operations against US and Allied overseas nuclear delivery bases and nuclear delivery forces at sea.

33. The variety of preparations undertaken, forces and tactics employed, and scale and weight of attack could range very widely within the broad limits set forth above. The indications obtained by intelligence would consequently vary in frequency, number and kind, and would have to be analyzed in terms of alternative hypotheses as to the precise form and scale of the initial Soviet attack. In many instances, intelligence could probably only point to the various types of attacks the USSR could be preparing to launch, although it might be able to provide a tentative judgment as to the more likely alternatives. Nevertheless, the foregoing discussion serves to illustrate that there is a wide variety of potential sources of warning indicators, any or all of which could serve in combination to provide a basis for the warning judgment.

WARNING FROM CERTAIN SOVIET PREPARATIONS FOR WAR

34. In this section we discuss the ability of the intelligence community to derive warning of Soviet attack on the US from various types of preparations the USSR might undertake: preparations for attack by long range striking forces, for clandestine attack, for operations by theater and naval forces, and for air and civil defense, as well as certain other preparatory activities designed to increase the general level of national readiness. In evaluating the significance of these various types of preparations, we must consider not only the ability of intelligence to detect them and the time necessary to recognize and evaluate them, but also the likelihood and timing of their occurrence and their validity as indicators of Soviet intentions. The analysis reflects our judgment that, in preparing for an attack on the US, the Soviets would try to strike a balance among the desirable objectives of achieving surprise, delivering an attack of great weight, preparing to defend against retaliation, and preparing to recuperate and to carry on the war. We regard this judgment as applicable to most circumstances in which the USSR might decide to attack, but as indicated in earlier paragraphs, there are conceivable circumstances which would alter our warning capabilities considerably.

35. In the discussion which follows, we have isolated the various types of preparations and activities the USSR might undertake so that we may assess our ability to derive warning indications from them. This procedure has elements of artificiality. It obscures the interrelationship among all types of indications arising from the likelihood that a very broad range of Soviet preparations and activities would be under way simultaneously, and it disregards the effect of analysis of the political context. In general, therefore, the degree of certainty with which the warning judgment could be made is likely to be greater than that implied by the following assessment of certain types of preparations and activities in isolation.

Preparations for Attack by Long Range Striking Forces

36. Our ability to derive warning from preparations by long range striking forces (ground-launched ballistic missiles, long range bombers, and missile submarines) is limited. Furthermore, this ability is declining as the attack role shifts increasingly to ballistic missiles, and as bomber forces increase the security of their operations and raise the level of their peacetime readiness. In addition, the more revealing indications pertaining to long range striking forces would be generated only a short time before an attack. On the other hand, if last-minute preparations by these forces were detected, they would probably be good indicators of Soviet intentions and could provide highly specific conclusions as to the likely time of attack.

37. Ground-Launched Ballistic Missiles. At the present time, intelligence has no means of providing advance warning of the use of ballistic missiles in an attack. To approach such a capability, we will have to identify operational units and their means of command and control, and also achieve an understanding of the operational concepts underlying the deployment and state of readiness of these forces. Even if we succeed in these tasks, our warning capability will remain severely limited by the very nature of the ballistic missile weapons system. It is probable that Soviet ICBMs could be ready for firing after preparations lasting a few hours at most, and that these preparations would involve very little movement or other noticeable activity.

38. There is a possibility that medium range ballistic missiles would need to be deployed forward into the Satellites or closer to Soviet borders in preparation for coordinated attacks against Western retaliatory bases and other strengths in areas peripheral to the Bloc. Such forward deployment need not be undertaken by the Soviets, however, and even should it occur it would probably require no more than a day and would be very difficult to detect because of our imperfect knowledge of the present locations of such units, the routes of movement they would employ, and the nature of the prepared launch sites they would require, if any. In sum, there is virtually no chance of obtaining indications of preparations by ballistic missile units at present.

39. Long Range Bombers. In any attack on the US at present or in the next few years, it is almost certain that the entire Soviet force of heavy bombers and tankers would be committed to operations against North America.⁶ It is probable that some portion of the medium bombers and tankers of Soviet Long Range Aviation would also be so committed, with the remainder allocated to targets peripheral to the Bloc. Medium bombers of Soviet Naval Aviation, equipped for the most part with antiship missiles, would probably also participate in initial Soviet operations by seeking out and attacking Western carrier task forces at sea. The levels of training and readiness of these bomber forces have improved considerably in the past few years, but it would probably still require a week or 10 days to bring this entire force of roughly 1,500 aircraft to peak readiness and to accomplish whatever redeployment was necessary prior to attack.

40. If the Soviets engaged in such a maximum effort, it would involve increased and abnormal flight activity, intensified maintenance activities, urgent logistic preparations, and possibly the preparation of special weapons. The Soviets would take strenuous measures to maintain security in these activities. Nevertheless, evidence of such activities would probably be detected in increasing quantity during the days preceding an attack, thus increasing the opportunities for intelligence to derive warning indications from their accumulation.

41. The chances of obtaining indications of the foregoing type remain good at present, although they have been materially reduced over the past year as separate, cross-checkable sources of information on these forces have diminished. Moreover, the interpretation of indications could not always be definite and specific, especially in a time of international tension. (In several past crises, most notably during the Iraq-Lebanon crisis, the Soviets placed their bomber forces on increased alert, presumably as a deterrent to the West and in preparation for the contingency of war.) However, the knowledge that the readiness of these forces was being increased could provide the basis for a preliminary warning which might be given a few days prior to a Soviet attack.

42. Increasing Soviet security has considerably degraded our ability to achieve timely detection of flights to Arctic staging bases, on which intelligence has heretofore placed great reliance for warning of attack on the US. Our expectation that the USSR would stage bombers through Arctic bases in such an attack rests on several considerations:

a. Long Range Aviation training exercises frequently involve small-scale flights by medium and heavy bombers from home bases in Western, Southern, and Far Eastern USSR to bases in the Kola Peninsula, the Central Arctic, and the Chukotsk Peninsula. Some bases in these latter areas are apparently maintained for temporary use by bombers of Long Range Aviation; two Arctic bases are known to have nuclear weapons storage facilities.

b. The range of the BISON jet heavy bomber is marginal for operations against the US. Refueled BISONs could conduct two-way operations against some targets in the US directly from home bases, landing at Arctic bases on the return trip, but in most cases this would require the aircraft to employ straight-line routes, to operate at altitudes and speeds calculated to minimize fuel consumption, and to forego evasive maneuvers, low altitude approaches, and other penetration tactics. For operational flexibility and good target coverage, BISONs should be staged through Arctic bases and refueled as well.

c. Given the small size of the heavy bomber force, Soviet delivery of an attack of great weight against the US would require the employment of medium bombers. A few BADGERs of Long Range Aviation are now regularly based in the Arctic; any others employed against the US would need to stage through bases in that area.

43. If the USSR staged a massive bomber attack through Arctic bases—an attack involving the departure from home bases of, say, 500 aircraft including the entire heavy bomber and tanker force and about a third of the medium bombers of Long Range Aviation—it would have to provide for last-minute maintenance stand-downs, deployment to staging bases, and servicing and fueling at staging bases. Based on present Soviet patterns of activity, we believe that at least a day or so would be required for these preparations and movements. The chances are better than even that some aspects of an operation of this size would be detected in time to provide warning before the Soviet bombers arrived at North American radar warning lines. There would always be a chance that the movement to forward bases was a threatening or practice maneuver rather than an attack. The problem of distinguishing between practice maneuver and impending attack would probably be greatest during the winter months, when most Soviet air exercises into the Arctic are conducted. But indications of this sort would produce urgent intelligence warnings, at least to the effect that an imminent attack was possible.

44. There is a possibility that the Soviets would limit their initial bomber attacks on North America to their heavy bomber force plus a few medium bombers. Security might be maximized by launching BEAR turboprop heavy bombers directly from home bases, with only BISONs and BADGERs employing Arctic bases. Intelligence could probably not detect and recognize the activities associated with the launching of such a reduced force of, say, 150–200 bombers and tankers in time to provide warning prior to their arrival at North American radar warning lines. Nor are we in a position to say how many more aircraft than this the Soviets could launch in an attack on the US before the chances of receiving advance warning indications became about even.

45. In support of long range bomber strikes on any scale, there would probably be activities not directly associated with the bombing units themselves which might indicate preparations for attack, perhaps as much as a few days in advance. These activities could include: intensified Soviet efforts to collect and report worldwide weather data; the imposition of very strict control over air traffic within the USSR, especially along routes northward from Long Range Aviation bases; and perhaps even sea and Arctic reconnaissance flights. Such indications, especially if they occurred within a short period of time, would strengthen whatever preliminary or specific warning might be given.

46. Submarines. The Soviets now have in operational units more than 50 submarines capable of being on station off US coasts for brief periods without refueling at sea. About 18 of these are conventionally powered missile-launching submarines believed to be equipped for surface launching of ballistic missiles with ranges up to about 350 n.m., and the remainder are conventional torpedo attack types. In addition, the Soviets probably now have half a dozen or more nuclear-powered submarines whose armament is not definitely known. Virtually all of these submarines are stationed in the Northern and Pacific Fleet areas, where they have direct access to the open seas. The most specific and firmest warning of Soviet attack on the US which might be derived from Soviet naval preparations would stem from the activities of these long range submarines, although indications could also be drawn from preparations by the remainder of the submarine fleet and by surface naval forces.

47. In recent years, Soviet submarines have conducted operations outside of Bloc coastal waters with increasing frequency. There is strong evidence that Soviet submarines have occasionally reconnoitered US coasts, but they have not established a regular pattern of patrols within missile-firing range of US targets. Unless they establish such a pattern, the Soviets, in deciding whether to employ submarines in initial attacks on the US, would have to weigh the risks of premature disclosure of intent against the advantages of additional weight of attack. The deployment itself would require two or three weeks, depending on the routes and tactics employed. This of course would preclude submarine participation in an initial blow if the Soviets made a sudden decision to attack on short notice. But assuming a Soviet decision taken well in advance, or a period of tension in which the Soviets desired to increase their readiness, there is a good chance that they would deploy some portion of their submarines from Northern and Pacific Fleet areas. Given enough time, this could be done gradually so as to minimize the risks of alerting the US.

48. We believe that under normal US readiness conditions and surveillance, there is some chance, though small, that a general departure into the open seas of Soviet submarine forces large enough to include all presently operational missile submarines would be detected in numbers sufficient to cause additional alert measures. There would be a fair chance that such forces approaching US coasts could be detected by our Sound Surveillance System, perhaps as far out as 400 n.m. Such detection would give rise to an alert, perhaps a few hours or a day before the submarines reached missile launching points. It would cause efforts by ASW forces to confirm the contacts and to establish surveillance, which in turn could lend specificity to intelligence warnings.

49. During times of alert, present US planning calls for additional forward sea and air surveillance. If the US had been alerted prior to Soviet submarine departure from home waters, the chances of detecting the movement of a force of Soviet submarines would be raised. If early detection were achieved, it could have the very significant effect of providing more specific warning information a week or two before the initiation of a Soviet attack on the US.

50. Future Trends. Intelligence capabilities to derive warning from preparations by Soviet ballistic missile forces may improve somewhat, but given foreseeable obstacles we believe they will remain very poor. As Soviet strength in ground-launched ballistic missiles grows, intelligence should achieve some identification of units, some understanding of the Soviet operational concepts regarding them, and possibly some capability to monitor their activities. There is a small area of hope that essential patterns of activity may become observable, reflecting various stages of readiness of ballistic missile forces, and that through interpretation of these and other indicators of increasing Soviet war readiness it may be possible to mount extraordinary collection efforts against missile forces at the right time. However, the short reaction times associated with ballistic missile systems could defeat all attempts to detect their imminent employment and to communicate this information in time to provide advance warning.

51. The chances of warning from preparations by long range bomber forces will decline. This trend will result in part from continuation of the trend towards increasing Soviet security in air operations. The utility of bomber redeployment as a short range indicator could be virtually eliminated if the Soviets established routine patterns of fairly large-scale activity at Arctic bases, and there will always be a possibility that heavy bombers need not stage through such bases at all. Most important, however, the growth of Soviet missile capabilities will shift the main strike role away from bombers. The probable Soviet employment of both bombers and missiles in initial strikes between now and at least 1963 may provide some temporary bonus to intelligence collection because of the Soviet requirement to coordinate their preparations.

52. The ability of intelligence to provide warning based on the activities of Soviet missile submarine forces will depend significantly on the extent to which improved submarines and missiles are introduced into these forces. US techniques for submarine detection, identification, and surveillance will probably improve, thus increasing the chances of deriving warning indications from the movements of currently-operational types of Soviet missile submarines. On the other hand, warning capabilities would be considerably less against Soviet nuclear-powered missile submarines designed for submerged launching of ballistic missiles from as much as 500–1,000 n.m. at sea, which we have estimated could become operational within the next year or so. Moreover, should the Soviets establish a pattern of routine submarine patrols within missile firing range of US targets, there would be very little chance of deriving warning indications from the activities of such submarines.

Preparations for Clandestine Attack

53. The USSR could also commit acts of war against the US clandestinely. In an initial attack it could, for example, employ nuclear, chemical, or biological weapons which had been introduced clandestinely into the US or into overseas bases. The ability of intelligence to give warning of an initial attack launched by such means would depend primarily on the possibility that some part of the Soviet clandestine plan had miscarried in a way which would provide disclosure, that some individual privy to the arrangements had defected, or on chance discovery. Discovery that the USSR was attempting to introduce a nuclear weapon into the US or one of its bases would lead intelligence to give its firmest warning of Soviet intent to attack. There is no way to estimate the chances of making such a discovery, since it would be a fortuitous event. On the other hand, we believe that the Soviets appreciate the consequences of disclosure, and that in light of the other means of attack available to them they would be very unlikely to attempt clandestine attack.⁷

54. Similarly, discovery of Communist plans for systematic sabotage of civil and military communications at a given time would provide very significant indications. Clandestine activities of a lesser order of importance, such as minor acts of sabotage on a large-scale, might contribute to our ability to give meaningful warning. We could not be certain, however, that such activities had been organized in conjunction with an attack on the US.

Preparations by Theater and Naval Forces

55. The range of actions needed to prepare the diverse Soviet ground, tactical air, and naval elements for general hostilities is sufficiently broad to provide a good chance of detecting increased readiness of these forces. Moreover, even in a war initiated by a massive nuclear exchange, some advance preparations by theater and naval forces apparently are regarded by the Soviets as necessary to protect those forces for subsequent operations, as well as to insure their readiness for quick action to take advantage of whatever surprise the initial Soviet attacks achieved. The time required to carry out these preparations, however brief, and the advisability of carrying them out before US retaliation destroyed transportation and facilities, argue strongly that some would occur before the first Soviet strikes reached US early warning lines, although the Soviets would make every effort to prevent disclosure of their intention to attack. In drawing conclusions from preparation by theater and naval forces, it would be difficult to distinguish Soviet motivation as between intent to attack the US, to take precautionary steps, or to establish a threatening posture for political reasons. This difficulty would increase during seasonal maneuvers of ground forces and would be greatest in a time of heightened international tension.

56. Theater Forces. Knowledge of the activities of Soviet theater forces rests heavily on observation of the forces in East Germany, although we have spotty intelligence coverage on forces within the USSR. Soviet ground and air units in East Germany are maintained in a high state of readiness, and they need not be reinforced prior to initiating attacks. It would probably require very little time for ground units and equipment to disperse from barracks to hastily prepared positions. But we believe the minimum time necessary to prepare all Soviet forces in Germany for wartime employment would be a few days to a week, even assuming a desire to minimize preparations in the interests of surprise.

57. The chances are good that irregularities in the behavior of Soviet forces in Germany would be detected by US and other Western intelligence sources. Recognition of an abnormal situation would depend to a degree on the time of year. It would be more difficult in the spring, summer, and fall, particularly during April, September, and October, when we have become accustomed to expect extensive Soviet preparations for training movements. The annual training cycle would also affect the time necessary for major Soviet ground elements to assemble in forward positions near the West German border. The required time could vary from a few hours during periods of normal training movement to as much as a week at certain other times of the year. Such a forward assembly of major elements, if it occurred, would give rise to the most specific warning which intelligence could derive from Soviet theater force activities. Preparations by airborne forces within the USSR would also be regarded as highly significant for warning, but our current ability to observe their activities is only fair.

58. Naval Forces. The bulk of the active Soviet naval forces, including major surface and submarine elements stationed in the Northern, Pacific, Baltic, Black Sea, and Mediterranean areas, is trained primarily for defense of Soviet coasts and for operations against surface ships. In recent years, anti-submarine warfare has received new emphasis. The necessity for the Soviets to begin carrying out some of these naval missions within a few hours after an initial attack on the US would probably require an inescapable minimum of advance preparations. Moreover, Soviet doctrine calls for the dispersal of naval forces from present concentrations to other bases in the event of war—such dispersal is frequently the introductory phase of major Soviet fleet exercises. While there is thus a good chance of naval preparations, including deployment and dispersal, these could be accomplished gradually and under conditions of great secrecy. They might take as little as a day or as long as two weeks, depending on their magnitude. Considering our total intelligence coverage, including that provided by forward sea surveillance off Soviet fleet areas, the chances of detecting and recognizing such preparations are fair.

59. Trends. Our ability to derive warning information from preparations by theater forces will probably decline somewhat, primarily because the present trend toward tightening Soviet security will continue. Coverage of Soviet theater forces in Germany will remain a critical factor. It could be sharply degraded by loss of intelligence access through Berlin or by Soviet measures to curtail the movements of Western military liaison missions in East Germany. If in the future the USSR substantially reduced its German garrison, there might from that time onward be a greater chance of reinforcement prior to the initiation of hostilities. We cannot count on this, however, because the Soviets might still regard whatever strength remained in Germany as sufficient to begin operations without reinforcements. Little change is anticipated in our ability to derive warning indications from the activities of naval forces other than submarines.

Defensive Preparations

60. In view of the threat posed by Western retaliatory power, the Soviet leaders would also undertake certain defensive preparations, especially in air and civil defense. Preparations of this sort would be good reflections of tension, but would be equivocal as to whether Soviet intentions were attack, defense, bluff, or deterrence. Because of their precautionary nature, defensive preparations might be poor indicators of the timing of a Soviet attack.

61. Air Defense. A portion of Soviet air defense forces, especially radars and fighter units near borders and along airline routes, are normally on alert. At times of tension or alarm, however, Soviet air defense alert forces are augmented—in the past, additional fighters have been placed on strip alert and surface-to-air missiles in the Moscow area have sometimes been moved from hold areas to launchers. At such times, the Soviets also impose more rigid controls over air traffic within the Bloc, and intensify their surveillance of air traffic within and near Bloc borders. We believe that because of the potential effects of US retaliation, there is an excellent chance that intensified air defense measures would precede Soviet initiation of hostilities against the US.

62. The Soviets would probably require at least a few days of maintenance and other preparations to bring their air defense system to maximum readiness, but a fairly high degree of readiness could be attained with little delay. Because of the number of units involved, their widespread locations, and the presence of many of them in areas accessible to Western intelligence coverage, the chances are very good that a general intensification of Soviet air defense measures would be detected. Final alerts and measures affecting civil traffic could be deferred until very late in a surprise attack situation, however, thus limiting to a few hours the time during which warning indications could be obtained.

63. Civil Defense. Measures which the Soviets could take to protect population, industrial, governmental, and other assets from the effects of retaliatory attack include the activation of civil defense units, final preparation of shelter, and evacuation of key personnel and possibly elements of the population from likely target areas. Published Soviet civil defense manuals make provision for several courses of action, evidently envisioning different amounts of warning of Western attack:

a. evacuation of some elements of the urban population and other deliberate preparations, assuming a few days or more of warning;

b. declaration of a “threatening situation” and short-term preparations such as readying urban shelters and evacuating civil defense units to the suburbs, assuming a few hours to a day of warning;

c. extremely limited preparations such as rapid movement of the population to urban shelters, assuming a few minutes to a few hours of warning.

64. In the interests of surprise, the USSR might decide to forego civil defense preparations until the last feasible moment, but to carry out any usefully comprehensive measures a start would have to be made before the initial strikes were sent off. Notification of the populace is apparently to be transmitted by wired public address speakers—at present, we could detect such notice only by the fortuitous presence of a Western observer at the location of one of these speakers when the announcement was made. But unless the Soviets decided to leave the populations of Moscow and other major cities unprotected, there is a very good chance that the effects of such notification on the behavior of the populace would be detected promptly by Western diplomatic, press, and other personnel in the USSR. Information concerning urgent civil defense activities, and especially of the evacuation of key government personnel, would serve to corroborate other warning indications.

65. Trends. The risk the USSR would be willing to accept as a result of neglecting some or all defensive preparations would depend in part on the degree of success which the Soviet leaders expected their own initial attacks to achieve. Despite likely improvements in their nuclear delivery capabilities, we believe that in elementary prudence, they would be unwilling in the foreseeable future to forego all preparations to receive a retaliatory blow. If the Soviet doctrinal emphasis on poststrike recuperability is any guide, then as the destructiveness of weapons increases and the interval between attack and potential retaliation decreases, the more essential become advance preparations to reduce initial losses and to protect national strengths, including population. The ability of intelligence to derive warning information from air defense preparations of the USSR will probably decline somewhat as air defense missiles replace fighter aircraft. The future utility of civil defense indicators will depend heavily on whether or not current Soviet programs are stepped up to the point where the civil defense system is normally in a high state of readiness. There is no evidence that the Soviets plan any such step-up.

National Mobilization

66. If the USSR undertook to mobilize its full war potential a great variety of indications would be obtained. Military measures could include call-up of reserves, retention of conscript classes beyond the time of normal release, activation of additional units, and intensified training programs. Economic and scientific measures would affect weapons development and production programs, allocation of materials and manpower, and utilization of transport. A major mobilization would involve the growing dislocation of Soviet national life over a period of months, during which time intelligence could give warning of progressively greater readiness for war. It is unlikely, however, that the pattern of national mobilization activities would justify more specific warning at any time during this period.

67. In the more likely circumstances preceding Soviet initiation of hostilities, the Soviets might undertake whatever partial mobilization measures were permitted by considerations of time and security. These could include various degrees of strengthening of cadre units, military pre-emption of communications and transport, medical preparations, and many other similar activities. The Soviets, for example, could in a few days call up the necessary personnel to bring all ground force units up to full strength, drawing upon the reserve system which they have maintained and are now expanding in connection with military personnel cuts. Those units normally maintained at cadre strength would require a few weeks’ training before they could be considered combat effective. If detected by intelligence, such Soviet preparations would serve to support or confirm other indicators and to amplify a general impression of ominous abnormality. In themselves, however, evidences of partial mobilization would not reveal Soviet intentions and would be only a poor guide to the timing of an attack, since it would always be possible for the USSR to attack with its ready forces.

Other Preattack Preparations

68. There is a host of other possible manifestations of Soviet preattack behavior, and we believe that some would be detected by intelligence. Many of these are peripheral to the actual readying of forces for attack, defense, recuperation, and followup military action, but like mobilization activities they could serve to strengthen the warning judgment. The chances are good, for example, that prior to an attack on the US some propaganda manipulation of the Soviet people would be required, if only to moderate the panic which could prevail if the populace, without prior warning, were suddenly ordered into shelters or told to evacuate at once to the countryside. Diplomatic indications which might precede an attack could include high level intra-Bloc meetings, efforts to secure the neutrality of certain non-Bloc nations, or even unusual behavior on the part of Soviet representatives in likely target nations. Intelligence would correlate such indications with evidence of Soviet physical preparations, but they would be very difficult to evaluate, especially in time of grave international crisis.

69. We are uncertain as to our ability to derive warning information from the behavior of Soviet intelligence, communications, and internal security organizations, in part because we lack a guide to likely preattack patterns. Would Soviet intelligence collection activities be stepped up prior to an attack or be held in reserve for postattack use? What technique would the Soviets use in attempting to mask an increase in urgent communications? Would the Soviets attempt to carry out their preparations without sharply restricting the movements of Western observers? We can conclude only that sharply intensified Soviet security—in communications or over Western observers—would reduce our ability to collect information but could in itself provide an input to the warning judgment. These same considerations would apply should the Soviets attempt to jam or otherwise interfere with critical Western communications.

70. Possible Soviet deception attempts could have a similar effect. These could range from diplomatic moves or propaganda adjustments designed to reduce tensions just before an attack to the planting of false reports or communications about Soviet readiness and intent. Such efforts could confuse US intelligence analysis at a crucial moment and impede accurate, timely judgments on other indications. On the other hand, any discovery that deception was being practiced would be regarded by intelligence as evidence of a possible Soviet intention to launch a surprise attack.

WARNING FROM A COMBINATION OF INDICATIONS

71. In the preceding section, we have summarized by category the intelligence warning of Soviet attack on the US which might be derived from various Soviet preparations and activities. In any true preattack situation, however, it is unlikely that indications would appear singly; it is probable that we would detect concurrent albeit fragmentary indications in a number of categories. Because we cannot be sure what combination of indications would actually appear prior to Soviet initiation of hostilities, no definite measure is possible of the mutual reinforcement and cross-confirmation derivable from many indications as opposed to a few. However, the degree of certainty with which the warning judgment could be made would increase with the number, variety, and interrelationship of indications detected, recognized, and judged to be valid.

72. The validity accorded to indications by intelligence and by policy officials would depend to a degree on whether or not these indications were plausibly explicable in terms of Soviet courses of action other than an attack on the US. If warning were derived solely from a mixture of indications from, say, Soviet naval dispersal, civil defense, and partial mobilization, it would in theory be no less valid than warning derived from observed preparations of bombers and ballistic missiles. The latter would be more specific and dramatic, but would be less likely to be available in time. The former would be more likely to be timely, but would be subject to greater ambiguity as to Soviet intent. Analysis of indications in all these categories, especially if they occurred in logical sequence, could permit intelligence to give successive warnings with mounting conviction.

73. Considering all the factors affecting the problem of warning, we believe that at present intelligence would detect some evidence of preparations associated with a Soviet decision to attack. The next stage, the interpretation of this evidence, would be more difficult. We think the chances are better than even that, in most circumstances of an actual Soviet decision to attack, intelligence could give warning of increased Soviet readiness, and therefore could infer a possible intent to attack. But intelligence could almost certainly not give firm warning of such an intention. Warnings of increased Soviet readiness and possible intent to attack could be given a few days or more before an attack; warnings of probable Soviet intent are likely to be given, if at all, only a few hours before attack.

74. There is little prospect for any major improvement in the firmness and explicitness of the warning which might be given. Over the next few years, intelligence will continue to refine its ability to collect, transmit, and evaluate indications of abnormal Soviet preparations and behavior. These gains will be offset by a decline in the number and accessibility of dependable military indicators as the main weight of the Soviet strike capability moves over to ballistic missiles. But unless there is a drastic change in Soviet strategic thinking or the Soviets acquire an assured capability to knock out US retaliatory forces in a single missile attack, the possibility of warning from physical preparations will not disappear. Indeed, the limited time between initial attack and potential retaliation in a missile exchange would virtually force the Soviets to undertake some physical preparations for defense and recuperation prior to launching the attack.

75. As missiles gain in importance and general Soviet readiness gradually rises over the years, along with indications of physical preparations, intelligence will have to place additional reliance for warning on the more ambiguous indicators not directly related to physical preparations. The political context, already of great importance because of the increasing fluidity of the international situation, will assume a larger role in the warning problem. Depending on the circumstances, analysis of the political context could strengthen or impede the warning judgment. In some cases, the first preliminary warning of possible Soviet attack might arise from a judgment that the USSR was about to take a political initiative involving great risk of war with the US, or that a crisis was developing in such a way as to prompt the USSR to prepare for war.

1. “Probable Intelligence Warning of Soviet Attack on the United States.” Top Secret. 22 pp. CIA Files, Job 79R01012A, ODDI Registry.
2. See NIE 11–4–60, “Main Trends in Soviet Capabilities and Policies, 1960–1965,” dated 1 December 1960 (TOP SECRET) paragraph 9. It should be noted that the Assistant Chief of Staff, Intelligence, USAF, dissented to that paragraph. He believes that the evidence of offensive missile and bomber production and deployment shows a definite intent by the Soviet rulers to achieve a clear military superiority at the earliest practicable date. He feels we are entering a very critical 24 month period in which the USSR may well sense it has the advantage. The Soviet leaders may press that advantage and offer the US the choice of war or of backing down on an issue heretofore considered vital to our national interests.
3. See NIE 11–4–60, “Main Trends in Soviet Capabilities and Policies, 1960–1965,” dated 1 December 1960 (TOP SECRET) paragraph 90.
4. It is possible that preliminary warnings would result in US precautionary measures which would lead the USSR to cancel or postpone a planned attack. In this case, what appeared to be a mistaken warning would in fact have been a correct one. Intelligence might have accomplished its warning mission, yet not be able to demonstrate that it had done so.
5. See NIE 11–4–60, “Main Trends in Soviet Capabilities and Policies, 1960–1965,” dated 1 December 1960 (TOP SECRET) Chapter IV.
6. Soviet operational strength in heavy bombers and tankers, as of mid-1961, is estimated at about 150 aircraft. Medium bombers and tankers are estimated at about 950 in Long Range Aviation and about 380 in Naval Aviation. The Assistant Chief of Staff, Intelligence, USAF, estimates the number of heavy bombers and tankers at about 175 and the number of medium bombers and tankers in Long Range Aviation at about 1,000.
7. For further discussion, see NIE 11–7–60, “Soviet Capabilities and Intentions with Respect to the Clandestine Introduction of Weapons of Mass Destruction into the US,” dated 17 May 1960 (TOP SECRET) paragraphs 2–4, and the footnote thereto by the Assistant Director, Federal Bureau of Investigation, who points out that a Soviet decision to employ this means would depend not only on Soviet capability with overt means to destroy US retaliatory capability; but also the US capability to launch retaliatory forces before their destruction by overt Soviet means.