211. Memorandum From Secretary of State Vance and the Director of the Arms Control and Disarmament Agency (Warnke) to the Chairman of the Joint Chiefs of Staff (Jones)1


  • Non-Proliferation Value of a Comprehensive Test Ban (CTB)

One of the most serious potential threats to our national security is the further spread of nuclear weapons. We believe that a major national security advantage of a CTB—in addition to the constraint it would impose on Soviet strategic force modernization—would be CTB’s contribution to the achievement of non-proliferation objectives.

By demonstrating the willingness of the nuclear powers to accept restraints on their own nuclear capabilities, CTB would put the U.S. in a stronger position to carry out our non-proliferation strategy. We could better press key non-nuclear states to accept restrictions on their activities.

The President has publicly repeated his commitment to a test ban; and the intense interest of the non-aligned nations, as well as our allies, in a test ban was expressed in the recent U.N. Special Session on Disarmament.2 Continued failure to reach a CTB would seriously impede our non-proliferation efforts and could result in considerable erosion of what we have achieved.

We believe that the longer the duration of the CTB, the greater the benefits. But even a three-year ban, if non-discriminatory, would have significant non-proliferation value. Following are some specific benefits.

[Page 520]

1. Prevent Testing by Threshold States.

A CTB would commit non-nuclear weapon parties to accept constraints upon nuclear weapon development. These nations would be unable to obtain either the political benefit or the initial proof of weapons afforded by tests. This would be important politically for nations which have not joined the NPT—notably India, Pakistan, Egypt, Israel, Argentina, Brazil, Spain, South Africa, and Saudi Arabia. Six of these nations are parties to the Limited Test Ban Treaty. A widely supported CTB—one that, unlike the NPT, could not be attacked as discriminatory—would be politically very costly for such states to reject. There are reasonable prospects that a substantial number of them will join. Even for those that choose not to adhere, the existence of a CTB could well be a factor inhibiting any decision to test.3

2. Strengthen the NPT

Most of the non-nuclear parties to the NPT have stressed the importance they attach to fulfillment of the reciprocal undertakings of nuclear weapons states to curb vertical proliferation. One of the steps most persistently urged is a comprehensive test ban treaty, which is considered a litmus test of nuclear power intentions. A CTB could make it easier to persuade4 additional states to join the NPT, and reduce charges of discrimination and of failure to fulfill our obligations under Article VI of that Treaty.5 It would also minimize the chances of withdrawal by countries, such as Yugoslavia and Nigeria, that have hinted at that possibility. If a CTB is in effect by 1980, it will improve the negotiating position of the United States in the NPT Review Conference.

3. Reinforcement of the Treaty of Tlatelolco

Argentina and Brazil, two states of primary proliferation concern who have not joined the NPT, have interpreted the Treaty of Tlatelolco as not foreclosing “peaceful” nuclear explosives. Since Tlatelolco could well enter into force at about the same time as a CTB, the latter would close out this possibility.

[Page 521]

4. India.

While Prime Minister Desai has declared that he will not authorize any further explosions,6 it is important to translate this into a treaty obligation binding India. Desai states that India will “support all non-discriminatory measures toward nuclear disarmament,” and indicated that a CTB would “remove a sensitive element of discrimination and bring the chances of acceptance of a non-proliferation treaty both internationally and nationally much nearer.” Last month Foreign Minister Vajpayee told U.S. Congressmen that India would join a non-discriminatory CTB. Given India’s standing in the non-aligned movement as well as the importance of Indian actions in this area in the wake of its 1974 test, Indian adherence to the CTB would have a beneficial effect on other countries, particularly Pakistan.7

Our other major non-proliferation objective in India—full scope safeguards—would be promoted by a CTB. At his January 5 press conference, Desai said “India will agree to full scope safeguards only if the nuclear powers, at least the big two, the United States and the Soviet Union, signed a comprehensive treaty to avoid all types of tests” and took certain other steps. In his recent meetings with Prime Minister Desai, the President placed great emphasis on the CTB as a major part of the solution to the safeguards problem.8 Since the Non-Proliferation Act of 1977 requires termination of U.S. nuclear aid to India if full scope safeguards are not in place in 18 months, a CTB may avert a serious division between the United States and India.

5. South Africa.

A CTB which South Africa9 joined would convert into a treaty obligation the assurance Prime Minister Vorster gave the President that South Africa would not explode a nuclear device.10 This would help reduce regional apprehensions about South African intentions as well as [Page 522] the risk of consequential decisions by others to go nuclear. In the near term, a CTB could advance the progress begun during Ambassador Smith’s recent visit in achieving South African adherence to the NPT and full scope safeguards.11

In summary, we believe that a CTB is a central element of our efforts to prevent the further proliferation of nuclear weapons.

  • Cyrus Vance
  • Paul C. Warnke
  1. Source: Library of Congress, Manuscript Division, Harold Brown Papers, Box 82, Comprehensive Test Ban Treaty #2. Secret. Copies sent to Brown, Schlesinger, and Brzezinski. A stamped notation at the top of the memorandum reads “SECDEF HAS SEEN, JUL 1978.” Underneath the date, Brown wrote “7/11 Dave McG—this should be of some help with JCS. HB.”
  2. The UN Special Session on Disarmament was held in New York from May 23 to June 30.
  3. In the right margin next to this paragraph, Brown wrote “This is less useful an exposition than it would be if it [illegible] of these countries specifically” and underlined the words “could well be.”
  4. Brown highlighted the portion of this paragraph that begins “Most of the non-nuclear parties” and ends with “easier to persuade” and wrote in the right-hand margin “same on this.”
  5. Article VI of the Non-Proliferation Treaty declared that signatories must pursue “negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament” and make progress towards a treaty “on general and complete disarmament under strict and effective international control.” (“Treaty on the Nonproliferation of Nuclear Weapons,” July 1, 1968, Documents on Disarmament, 1968, pp. 461–465)
  6. On June 9, Desai told the UN Special Session on Disarmament that India had “abjured nuclear explosions even for peaceful purposes.” (“Address by Indian Prime Minister Desai before the Special Session of the General Assembly Devoted to Disarmament: Indian Nuclear Policy [Extract],” June 9, Documents on Disarmament, 1978, pp. 382–383)
  7. Above and to the right of this paragraph, Brown wrote “useful.”
  8. See footnote 4, Document 206.
  9. Brown circled and drew a line from the words “South Africa” and wrote “would it?” above and to the right of this paragraph.
  10. Telegram 247704 to London, Paris, and Bonn, October 15, 1977 reported that on September 13, South African Foreign Minister “Pik” Botha had handed Ambassador Bowdler a letter from Vorster to Carter that “led off with reiteration of SAG’s previous assurances that South Africa does not have or intend to develop nuclear explosives for any purpose, that Kalahari is not a nuclear test site, and that there will not be any nuclear testing in South Africa.” (National Archives, RG 59, Central Foreign Policy File, P840081–2508)
  11. Gerard Smith, the President’s Special Assistant for Non-Proliferation Matters, visited South Africa from June 26–28 to discuss nuclear issues.