257. Special National Intelligence Estimate1

SNIE 11-13-68

US INTELLIGENCE CAPABILITIES TO MONITOR CERTAIN LIMITATIONS ON SOVIET STRATEGIC WEAPONS PROGRAMS

The Problem

To estimate the capabilities of US intelligence to monitor by national means limitations on certain Soviet strategic capabilities over the next five years or so.

[Page 647]

Note

The Intelligence Community has been asked to review SNIE 11-10-67, titled as above, dated 14 February 1967, and to update that estimate because of the recent Soviet proposal regarding the discussion of certain arms control measures.2 In this estimate we give primary consideration to the ability of intelligence to monitor the deployment of certain strategic weapon systems, but we also consider the likelihood of our detecting certain qualitative improvements to various weapon systems.

Conclusions

A. In the continued absence of a large-scale Soviet program of deception and concealment, we believe that we would almost certainly detect any extensive new deployment in strategic forces, although the Soviets could probably effect small-scale increases without our knowledge. The timing of detection and identification would vary with the nature and size of the program. We probably would identify a land-mobile offensive system, for example, but [1-½ lines of source text not declassified] it would be difficult to determine the magnitude of such a force.

B. We would almost certainly detect any large-scale test program, but we could not always expect to assess accurately the test objectives or even the precise nature of the system being tested. Our capabilities are generally better in the case of offensive than of defensive weapons. We believe, for example, that we could detect and identify Soviet testing of multiple independently-targeted reentry vehicles (MIRVs) for intercontinental ballistic missiles. We could probably also detect test activity associated with an antiballistic missile (ABM) system, [1-½ lines of source text not declassified].

C. Our capabilities for detecting qualitative improvements in the deployed forces are better in the case of defensive weapons than offensive ones. To optimize a surface-to-air missile (SAM) system for an ABM role would require such extensive changes that some would almost certainly be detected and identified [2-½ lines of source text not declassified]. We see no prospect of determining whether MIRVs (if developed) or other significant improvements had been incorporated in deployed offensive missiles.

D. Soviet employment of deception and concealment on a large-scale would, of course, degrade our capabilities. While we still believe that substantial new deployment would almost certainly be detected, detection would come later in the program, [6 lines of source text not declassified].

E. Factors affecting intelligence collection will vary over the period of this estimate, but intelligence is not expected to be able to guarantee [Page 648] that the Soviets have not violated one or more provisions of an agreement.

F. [4 lines of source text not declassified]

  1. Source: Johnson Library, National Security File, Intelligence File, Arms Limitation Talk, Box 11. Top Secret; [code word]; Controlled Dissem; Limited Distribution.
  2. See footnote 6, Document 181.