147. Memorandum From Director of Central Intelligence Helms to President Johnson 1



  • National Intelligence Estimate 11–3–66, “Soviet Strategic Air and Missile Defenses,” dated 17 November 1966

Attached is National Intelligence Estimate 11–3–66, “Soviet Strategic Air and Missile Defenses.”2 It is the third in our current series of estimates on Soviet military capabilities. In my judgment, its conclusions can be summarized as follows:

The crucial question in this estimate concerns the status of Soviet defense against ballistic missiles. We know the Soviets have been engaged in research and development in this field for more than ten years. The intelligence community is agreed that an anti-ballistic missile system has been under construction in the Moscow area since 1962 and will begin to be operational in the next year or two. It will probably have good capabilities against a limited-scale attack on Moscow by present US ICBMs. We [Page 451]believe that its effectiveness could be reduced by advanced penetration systems, and that it could not cope with a very heavy attack or with Polaris attacks from certain directions. At present there is no indication that this system is being installed anywhere else in the USSR. (I might add that I am confident that we could detect the installation of such a system elsewhere, perhaps two or three years before it reached operational status.)

There is, however, another new defense system under construction at a number of locations. It will begin to be operational next year. The intelligence community does not have enough information about this system to be certain of exactly what it is designed to defend against—whether ballistic missiles or aerodynamic vehicles. The general nature of the system, its equipment, and the pattern of its deployment lead me to believe it is an improved defense against high-speed, high-altitude aircraft, and also against the air-to-surface missiles that such aircraft may launch. But I cannot rule out the possibility that it is a defense against ballistic missiles. My views about this system are shared by the intelligence officers of the Department of State, the US Navy, and the Atomic Energy Commission, and by the Director of the National Security Agency.

Disagreement with these views is expressed by the Director of the Defense Intelligence Agency and the intelligence officers of the US Army and US Air Force. Their view is that while a confident judgment cannot now be made as to whether this system is for defense against ballistic missiles, aerodynamic vehicles, or both, it is more likely to be an anti-ballistic missile system with an additional capability to defend against high-flying supersonic aerodynamic vehicles. (Because of the uncertainties and our differences of view, we have included in the estimate an evaluation of the capabilities of this system in both roles.)

We are all agreed that the Soviets could have a limited anti-satellite capability now. Furthermore, they are building a space surveillance radar network which could support a much improved system. In a year or so they may be able to destroy our reconnaissance and other satellites by non-nuclear means; they may explore techniques for neutralizing satellites without destroying them. But we do not think they would actually try to neutralize or destroy US satellite unless they thought war were imminent or unless there were other special circumstances, such as an occasion in which they thought they were retaliating against US interference with their satellites.
The USSR has excellent defenses against present Western bombers operating at high and medium altitudes. Present systems will become less effective as the US introduces higher performance aircraft and air-to-surface missiles. The Soviets are working to improve their capabilities against these prospective threats, in part by developing much better interceptor [Page 452]aircraft and air defense control systems. Their low altitude defense is now a major weakness and will remain so for at least the next several years.

This estimate on Soviet strategic defenses completes our present series on the main elements of Soviet military capabilities.

I commend the entire document to your attention, especially its more formal Conclusions.

  1. Source: Johnson Library, National Security File, Intelligence File, Miscellaneous CIA Intelligence Memoranda, Box 14. Top Secret; Handle via Talent-Keyhole-COMINT Channels Jointly. An attached note from Rostow to President Johnson, December 4, 1 p.m., briefly summarized NIE 11–3–66 and added: “You will wish to read Dick Helms’ evaluation of the evidence on Soviet ABMs plus, perhaps, the summary—or even more. It is the foundation on which tough decisions are coming up.”
  2. Document 146.