7. Memorandum From Secretary of Defense Brown to President Carter1


  • Arms Control for Antisatellite Systems

(S) At the August 4, 1977 meeting of the Policy Review Committee on PRM–23,2 it was decided that a separate paper on antisatellite activities and arms control should be forwarded for your review and decision. That Decision Paper is enclosed along with an Issues Paper3 which contains a more detailed discussion of the issue.

(S) Because of the importance of this issue and the widely differing views on the approach we should take in our proposal to the Soviet Union, you may wish further discussion of this subject at the NSC level prior to your decision.

Harold Brown


Decision Paper4



What should be the U.S. policy on antisatellite (ASAT) activity and ASAT arms control?


The U.S. has offered to propose ASAT arms limitations to the Soviet Union. In developing approaches for the discussions, a fundamental consideration is the need for a U.S. ASAT capability.

[Page 24]


Both the U.S. and the USSR have and are further developing satellite capabilities in space for a range of activities spanning peacetime, crisis and wartime. These include treaty verification, national and military intelligence, weather, navigation, communications and attack warning. Both sides are increasing the use of satellites as sources of tactical intelligence to provide near-real-time photography, electronic ferreting, and radar targeting of military assets.

The Soviet Union currently has an advantage over the U.S. in antisatellite capabilities. They have an orbital interceptor which has been judged to be operational [8½ lines not declassified]

The U.S. has no ASAT capability. A nuclear interceptor system was operational until 1975 at Johnston Island. Currently, the U.S. is developing a new interceptor which is planned for testing by 1981. [3½ lines not declassified]


On the one hand:

Limitations on Soviet capabilities to attack U.S. satellites would be desirable since the U.S. is becoming increasingly dependent on its space assets, and relies on a smaller number of more sophisticated satellites than the USSR.

There has never been a confrontation in space and treaties have tended to give space a special status as a peaceful arena where both sides can work cooperatively.

ASAT limitations might preclude a potential arms race in space with its attendant action-reaction cycles, public concerns, increased defense costs and potential instabilities.

On the other hand:

The U.S. must assess the need, independent of Soviet ASAT capabilities, for a U.S. ASAT system to counter threatening Soviet satellites.

There are difficult treaty verification problems in this area.

Incentives to cheat may be greater than under previous agreements. Because each side has a small number (6–15) of critical satellites, small numbers of ASATs could be decisive. This is in contrast with current treaties limiting ICBMs and ABMs, where stability is not affected by small numbers of weapons.


Under all of the approaches discussed below, U.S. ASAT research and development activities will continue, and be modified to con[Page 25]form with any agreements reached during negotiations. The four approaches are:

1. No Agreement: Do not seek an agreement limiting ASAT systems. This does not preclude initiatives to further limit the likelihood of peacetime interference. For example, the U.S. could propose under the existing Agreement on Measures to Reduce the Risk of Outbreak of Nuclear War, to show restraint in ASAT testing during crises.

2. Emphasis on Peacetime Problems: Do not attempt to limit the capabilities of ASAT system but focus on peacetime problems and on establishment of thresholds for use. We would propose a peacetime sanctuary for all satellites.

3. Selected Limits: Seek bans on types of systems which do not yet exist, such as high-altitude interceptors and laser weapons in space, but permit each side to test and deploy low-altitude ASAT interceptors, electronic warfare, and ground-based laser ASAT systems.

4. Relatively Comprehensive Agreement: Seek a relatively comprehensive agreement which would ban all ASAT capabilities except electronic warfare. Electronic warfare is excluded because of verification difficulties. The ban would prohibit testing, deployment or use of any ASAT for physical attack on satellites. The current Soviet orbital interceptor would be dismantled.

—A variant (4A) would be a fully comprehensive ban on all forms of ASAT including electronic warfare.


[1 paragraph (4 lines) not declassified]

State and ACDA favor a comprehensive ban on ASAT systems in order to avoid cycles of action-reaction competition. Such an agreement would enhance the survivability of U.S. satellites, on which we increasingly depend for intelligence collection, verification, early warning, and communications. A ban on testing, deployment, and use of ASAT systems would contribute to stability by easing concerns about pre-emptive attack on critical satellites. The present Soviet interceptor is relatively unsophisticated; future Soviet ASAT systems would be much more difficult to counter. Measures short of a comprehensive approach would permit an expansion of Soviet ASAT capabilities, which would make maintaining the survivability of U.S. satellites more difficult. Verification would be difficult, but testing and in some cases construction of an ASAT system would be subject to observation. State and ACDA favor Approach 4.

In the OSD view, antisatellite negotiations should be directed toward a ban on peacetime interference. Such a ban would reinforce the principle of noninterference in peacetime and establish a threshold beyond which specific actions will be considered hostile. This approach [Page 26] recognizes that we must assume the Soviet Union could retain its existing capability even in the presence of a comprehensive ban. Elimination of these capabilities could not be reliably verified and confidence in the system in the absence of testing could be quickly regained. This system would be effective against such critical low altitude systems as the current near-real-time imaging system. In such a situation it would not be prudent to assume an ASAT agreement would be a suitable substitute for survivability measures. Furthermore, U.S. counteractions in survivability and ASAT development could take several years. Therefore, the OSD feels the U.S. should develop an ASAT capability. Toward these ends, OSD favors Approach Two.

In the JCS view, a ban on ASAT activities would concede existing Soviet capabilities, since their elimination cannot be verified. Conversely, such a ban would deny the U.S. the capability to develop a counter to military-related USSR space systems, particularly those which may constitute a direct threat to U.S. forces. Arms Control agreements cannot be used as a substitute for survivability of U.S. space systems; to do so would be to invite denial of U.S. use of space systems for a critically long period during a war given the likelihood of unilateral treaty abrogation at the outset of conflict. An agreement to prevent testing of an orbital ASAT has two drawbacks. First, Soviet confidence in their current system would not be appreciably reduced. Second, the U.S. would be unable to overcome the current Soviet advantage. Therefore, the JCS believe the U.S. should develop an ASAT capability and further that the U.S. should not enter into any agreement that would ban ASAT research, development, testing, and deployment.

  1. Source: Carter Library, National Security Council, Institutional Files, Box 41, Folder 3, PRM–23 [3]. Top Secret; Talent Keyhole; Control System Only.
  2. See Document 5.
  3. Attached but not printed.
  4. Top Secret; Talent Keyhole; Comint.
  5. The term ASAT includes any physical or [less than one line not declassified] on space systems. [Footnote is in the original.]