228. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon1


  • UK Decision on Polaris Improvement

Prime Minister Heath has sent you a message to inform you of the British Government’s decision to continue with a program to improve their Polaris missile warheads rather than procure a modified Poseidon warhead (Tab C). He hopes that you will confirm your previous agreement in principle to collaborate on the Polaris improvement project and expresses his appreciation for your generous offer of the Poseidon system. Since the UK hopes to announce this decision in their annual Defense White Paper, subject to your agreement, the Prime Minister asks if you could indicate to him your decision by January 25, 1974.

The British decision is mainly motivated by economic considerations. The Prime Minister notes that domestic problems, including the energy crisis, have forced a retrenchment in spending, but that his government is determined that this retrenchment not affect the UK’s [Page 734] NATO commitments. Thus, he has decided on the less costly alternative of improving the existing Polaris warhead for the UK nuclear submarine fleet, rather than undergo the expense of converting to a non-MIRV version of our Poseidon missile.

The Polaris improvement program involves adding to the three multiple reentry vehicles (MRV) a package of penetration aids that will ensure a British capability to overcome the existing Soviet ABM defenses. We have been cooperating with British experts on the initial experimental phase of this improvement package, but have not made a further commitment to the development, pending a British decision on whether to shift to the Poseidon.

If you agree to proceed with the Polaris project, we will probably have to provide space in our underground nuclear testing program for some UK tests of their modified warhead and for testing of the missile itself on our test ranges. This was envisaged from the outset, though no formal commitment was made. Your agreement to the Prime Minister’s request will permit the program to go forward. The British realize, however, that there is no guarantee that their modification of the Polaris warhead will succeed, since it is a new concept with which we are not thoroughly familiar.

There are no problems in agreeing to cooperate with the UK on this decision. From our standpoint, it is easier to accommodate the British decision on improving the Polaris than had the UK chosen to procure the Poseidon technology. Accordingly, I recommend that you confirm your agreement with the Prime Minister to collaborate in the project.


1. That you authorize transmittal of the attached message via the Cabinet Line to the Prime Minister, confirming your agreement to collaborate with the UK on the Polaris improvement project (Message at Tab A).

2. That you authorize me to issue the memorandum at Tab B, instructing the relevant departments and agencies to proceed with the UK project and extend our cooperation.

  1. Summary: Kissinger discussed the UK decision on Polaris improvement.

    Source: Library of Congress, Manuscript Division, Kissinger Papers, Box TS 28, Great Britain, Chronological File, January–April 1974. Top Secret; Sensitive. Sent for action. Attached but not published is Tab A, an undated message from Nixon to Heath; and Tab B, an undated memorandum signed by Scowcroft on Kissinger’s behalf to Schlesinger, Ray, and Rush. Tab C was not attached. Kissinger did not initial the memorandum and Nixon did not indicate his preferences among the recommendations; however, an attached undated note from Scowcroft reads, “Action approved verbally by the President, January 17, 1974.” Heath’s undated message to Nixon, sent under cover of a January 2 letter from Cromer, is in National Archives, Nixon Presidential Materials, NSC Files, Kissinger Office Files, Box 63, Country Files, Europe, General, Exchange with the UK—SLBMs (2 of 2). Nixon’s reply, in message WH40301 to Heath, January 19, is ibid., NSC Files, Box 431, Backchannel, Hotlines (all circuits) PRESUS IN/OUT thru Aug. 9, 1974.