Archive (Reagan Library)

Cold War: McFarlane (& others) letters to Thatcher (SDI briefing) [declassified 2000]

Document type: Declassified documents
Venue: White House & Dept of Defense, Washington D.C.
Source: Reagan Library: NSA Head of State File (Box 36)
Editorial comments: Declassified 28 Mar 2000.
Importance ranking: Major
Word count: 688 words
Themes: Defence (arms control), Foreign policy (USA), MT contacts with Ronald Reagan

Declassified F96-107#324
By SMF, NARA, Date 3/28/00

(1) McFarlane to Thatcher, 29 Jan 1985:

White House Situation Room


January 29, 1985

Dear Mrs. Thatcher,

I am forwarding letters from Secretary Weinberger and General Abrahamson along with my own best wishes and deep appreciation for the opportunity to meet with you earlier in the month. General Abrahamson’s clarification is most timely and contributes to a better understanding of a technically complex policy issue. We will continue to refine our views on these and other important policy issues and value the chance to discuss them with you and your advisors.

With best wishes,
Robert C. McFarlane

[end p1]

(2) Weinberger to Thatcher, no date:

Dear Mrs. Thatcher,

I wanted to especially thank you for the opposition to present the technical side of the President’s Strategic Defense Initiative. We feel that very substantial progress is being made, although there is a long way to go.

The key to that progress is the thousands of people in government and in industry who are already working on the project. Our confidence is enhanced because they represent many of our best minds. Over the next year, we hope to create additional opportunities for your people to meet with our experts so they will gain an informed, first-hand impression of the issues and the program.

I have also attached a letter from General Abrahamson expressing his appreciation for the opportunity to meet with you. He provides some additional points in answer to your concern about “automatic response”.

My very best wishes to you. I am looking forward to our next opportunity to discuss the Strategic Defense Initiative further, as well as the many new projects we have underway that are so satisfactorily improving our joint security.

Caspar Weinberger

[end p2]

(3) General Abrahamson to MT, no date:

Dear Mrs. Thatcher,

It was a great privilege for me to be able to present to you the technical progress that is being made on President Reagan’s Strategic Defense Initiative. We all particularly appreciate that you were willing to devote so much time to the subject.

I realized after our meeting that I answered one of your key concerns – the requirement for “automatic response” – in a narrower technical sense than you intended by your question. The key “authorization-to-fire” features are not yet defined. However, principles are now at hand which could clearly be built into a future system. For example, if one or two missiles were to be detected rising from the Soviet Union, extra delay time could be accepted to establish whether they were a threat or merely peaceful space launches. That extra measure of caution would be quite acceptable because a small number of threatening objects could be easily destroyed late in their trajectory by a multi-tiered defense system. Agreement on prior notification of peaceful space launches could also reduce risks of miscalculation even further.

On the other hand, if independent surveillance systems reported a large attack, a rapid response would be required. Human intervention for any defensive response of various points will provide fur assurance. The most important point to keep in mind is that even in the unlikely event of a mistaken launch of defensive systems, such action would only entail the emission of small, precise levels of energy directed randomly at empty points [end p3] in space. This contrasts most dramatically with the risk some people sometimes refer to in connection with launching offensive missiles rapidly for second strike retaliation.

We realize that this area, as other areas of Strategic Defense Initiative research, requires a great deal of additional study and attention. As the President has directed, we will continue to keep members of your government fully apprised of our progress. Thank you again for the opportunity to meet with you. My best wishes and prayers for you and the extraordinary leadership you are providing your nation.

James A. Abrahamson
Lieutenant General, USAF
Director, Strategic Defense Initiative Organization