Foreign Relations of the United States, 1981–1988, Volume XLIV, Part 1, National Security Policy, 1985–1988

235. Memorandum From the Chairman of the Joint Chiefs of Staff (Crowe) to the Director of the Strategic Defense Initiative Organization (Abrahamson)¹

JCSM–93–87

Washington, June 23, 1987

SUBJECT

• Joint Ballistic Missile Defense Operational Requirements for Phase I Ballistic Missile Defenses (U)

1. (S) The United States continues to adhere to the concept of deterrence and, should deterrence fail, the concept of denying Soviet war aims as the means for preserving the security of the United States and its allies. The Joint Chiefs of Staff have stated² that ballistic missile defense (BMD) could enable the United States to fundamentally change its strategic assumptions regarding deterrence, permitting a shift of emphasis from strictly offensive to a more balanced offensive and defensive orientation. Effective defenses against ballistic missiles could significantly increase Soviet uncertainties regarding a weapon’s ability to penetrate the defenses and destroy US and allied targets. Difficulties in predicting vulnerability and outcome could make Soviet military planners much less likely to contemplate initiating a ballistic missile attack, even in crisis circumstances.

2. (S) The Joint Chiefs of Staff will provide³ operational requirements for future BMD. The long-term objective is for a thoroughly effective defense that will protect the United States and its allies from the threat of attack from ballistic missiles of all ranges. To achieve this objective, it is clear that a strategic defense system will have to be deployed incrementally over time. This memorandum sets out the operational requirements for Phase I of a multiphase BMD system. Phase I, prior to deployment of following phases, must, in combination with our national strategic offensive capabilities, be capable of creating sufficient uncertainty in the Soviet war-planner’s mind to dissuade him from attack. Requirements for subsequent phases will be developed after future analyses of the evolving threat.

3. (S) Phase I BMD will serve as a first step toward protecting the United States and its allies from ballistic missile attack. It will also be a significant complement to today’s sole reliance on US strategic nuclear retaliatory forces as a deterrent disincentive to a potential Soviet first strike. However, it is important that Phase I not be considered a complete BMD system. Planning, research, evaluation, and testing for subsequent phases must lead to an evolving multiphase BMD system that incrementally builds upon Phase I to achieve sufficient defense effectiveness and robustness to discourage proliferation of the Soviet threat and introduction of countermeasures—and, ultimately, negate the utility of Soviet offensive ballistic missile forces.

4. (S) The operational requirements are based on the assumption that the primary mission of US strategic BMD is to:

a. Enhance the future deterrent posture.

b. Contribute, should deterrence fail, to denial of Soviet war aims and limit damage from strategic ballistic missile attack.

5. (S) For the Phase I BMD system, the operational requirements that follow address the portion of a massive Soviet nuclear attack comprised of the first wave (approximately 4,700 RVs of which at least 2,500 are SS–18 delivered RVs) of the first strike (approximately 8,500 RVs) of the [1½ lines not declassified] as detailed⁴ in the baseline DIA BMD threat assessment for 1996.

6. (S) The Joint Chiefs of Staff believe Phase I must be sufficiently effective to measurably stress Soviet war plans and also provide near-perfect protection against small ballistic missile attacks. Accordingly, Phase I must fulfill the following system goals:

a. Limit the damage that can be expected from the leading edge or early phases of wave one of a major Soviet nuclear attack.

b. Ensure high defense effectiveness against attack of limited scope (e.g., accidental/unauthorized launch, third nation attack, limited Soviet attack).

c. Destroy as many attacking RVs as possible during the boost and post-boost phases of their flight.

7. (S) To meet the system goals, Phase I must possess certain system characteristics. Phase I must be able to:

a. Ensure that sufficiently comprehensive and timely tactical warning and attack verification data will be provided to the responsible CINC so that a thorough assessment can be made before his decision to engage with defensive forces. Given the potentially severe consequences of an accidental or inappropriate activation of the strategic BMD system, a firm military requirement exists for man-in-the-loop control. As a consequence, the Phase I system design must provide for an appropriate man-in-the-loop decision time for weapon system activation.

b. Survive under attack long enough to ensure that minimum defense effectiveness objectives can be met. The BMD system must be sufficiently survivable to operate effectively throughout the boost and post-boost flight phases of the Soviet ballistic missile attack. The ground-based portions of the BMD system must survive until its interceptor assets have been expended in the late-midcourse and terminal flight phases of the attack.

c. [1 paragraph (13½ lines) not declassified]

d. [1 paragraph (10½ lines) not declassified]

8. (S) Phase I must be able to defeat the dynamic structure of the Soviet attack by denying the time-critical goals of the leading-edge component of the attack through the application of multiple defense layers (e.g., denying Soviet goals by using the boost/post-boost interceptors to break up the targeting strategy of an attack and then using the midcourse interceptors to enforce flexible and adaptive defense). This will necessitate that the defenses provide their peak performance against the leading edge of the attack by destroying a high number of attacking ballistic missiles during their boost and post-boost flight phases.

Ideally, operational requirements would be stated in terms of a quantitative, time-dependent performance that would set forth initial defense effectiveness and allowable reduction in that effectiveness over the course of the first wave battle, due to weapon expenditure and enemy defense suppression, for each of a series of possible attack scenarios. Given that it will take some time to develop such a rigorous statement, system characteristics given in subparagraphs 7c and d, above, provide quantitative performance thresholds, based upon aggregate measures of effectiveness, to provide a benchmark against which to scope Phase I system effectiveness. It must be recognized that these initial descriptions of BMD primary mission performance must be used with due regard to the time-dependent nature of the BMD performance requirement.

9. (U) The Joint Chiefs of Staff will continue analytic work to refine BMD operational requirements periodically throughout the SDI acquisition process, with particular emphasis on quantifying the time-dependent requirements for BMD.

For the Joint Chiefs of Staff:

William J. Crowe, Jr.
Chairman
Joint Chiefs of Staff

1. Source: Reagan Library, Fred Ikle Files, Arms Control (President Gorbachev)—1986–88. Secret.
2. JCSM–66–87, 15 May 1987, “Justification for Major System New Start for the Strategic Defense Initiative Program for Ballistic Missile Defense Research” (U) [Footnote is in the original.] Not found.
3. DOD Directive 5141.5, 21 February 1986, “Strategic Defense Initiative Organization” (U) [Footnote is in the original.] Not found.
4. DIA Memorandum, S–1037/VP-TAO (SDIO), 23 April 1987, “Threat Development for Ballistic Missile Defense Operational Concepts and Requirements” (U) [Footnote is in the original.] Not found.