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The Battle of the Letters, 1963: John F. Kennedy, David Ben-Gurion, Levi Eshkol, and the U.S. Inspections of Dimona

Published: May 2, 2019
Briefing Book #671

Edited by William Burr and Avner Cohen

For more information, contact:
For more information contact:
Avner Cohen at 202-489-6282 (mobile), 831-647-6437 (office) or avnerc@miis.edu
William Burr at 202/994-7000 or nsarchiv@gwu.edu.

Kennedy Warned Israeli Leaders in 1963 That U.S. “Commitment and Support” Could be “Seriously Jeopardized” Absent Inspection of Dimona Reactor

U.S. Intelligence Estimated That by Mid-1960s Dimona Could Produce Enough Plutonium For “One or Two Weapons A Year”

Washington D.C., May 2, 2019 - During 1963, President John F. Kennedy was preoccupied with issues such as Vietnam, the nuclear test ban negotiations, civil rights protests, and Cuba. It is less well known, however, that one of his most abiding concerns was whether and how fast Israel was seeking a nuclear weapons capability and what the U.S. should do about it. Beginning in April 1963, Kennedy insisted that the Israeli leadership accept regular bi-annual U.S. inspections, or in diplomatic language, “visits,” of Israel’s nuclear complex at Dimona in the Negev Desert. Prime Minister David Ben-Gurion and his successor, Levi Eshkol, tried to evade and avoid inspections, but Kennedy applied unprecedented pressure, informing them bluntly, in a near ultimatum tone, that Washington’s “commitment to and support of Israel “could be “seriously jeopardized” if it was thought that the U.S. government could not obtain “reliable information” on the Dimona reactor and Israel’s nuclear intentions.

The full exchange of letters and related communications between Kennedy, Ben-Gurion, and Eshkol, published for the first time today by the National Security Archive, illustrates both Kennedy’s tenacity and Israeli leaders’ recalcitrance on the matter of Dimona. Surprised by the U.S.’s firm demands, Eshkol took seven weeks, involving tense internal consultations, before he reluctantly assented. Retreating from a near-diplomatic crisis, both sides treated their communications on Dimona with great secrecy.

Today’s posting of declassified documents from the U.S. National Archives system, including presidential libraries, provides a behind-the-scene look at the decision-making and intelligence review process that informed Kennedy’s pressure on Israeli prime ministers during 1963. Among the documents are:

  • National Intelligence Estimate 30-63, “The Arab-Israeli Problem,” from January 1963, which estimated that if the Dimona reactor “operated at its maximum capacity … [it] could produce sufficient plutonium for one or two weapons a year.” This NIE was declassified in 2017.
  • A letter from a U.S. diplomat in Tel Aviv who concluded that the detection of an Israeli decision to initiate a “crash” emergency nuclear program would require “a fairly careful watch on the activities of the dozen or so top scientists.” This document was declassified in 2018.
  • A State Department memorandum supporting bi-annual inspections of the Dimona reactor to monitor the use of nuclear fuel. Without U.S. inspections, Israel could discharge spent fuel at six-month intervals “to produce a maximum of irradiated fuel for separation into weapons grade plutonium.”
  • Kennedy’s statement to French Foreign Minister Couve de Murville that Israel’s nuclear program had put that country in a “stupid” position by giving “a pretext to the Russians, who are retreating in the region, to indict us before world opinion, and perhaps not without reason.”
  • A memorandum of conversation from August 1963 in which a British diplomat reported on “new disturbing signs” of Israeli official interest in nuclear weapons. Declassified in 2016.
  • The detailed report of the January 1964 U.S. inspection of Dimona that resulted from Kennedy’s pressure on Ben-Gurion and Eshkol.

Some of the documents in today’s posting, such as the Kennedy-Ben-Gurion-Eshkol correspondence, were declassified in U.S. or Israeli archives during the 1990s, but have not been widely available.[1] Others, as indicated above, were declassified in recent years. Moreover, the French translation of Kennedy’s statement to Couve de Murville meeting has never been rendered into English before. Other documents relating to the Ben-Gurion/Kennedy confrontation remain classified at the U.S. National Archives. Significant CIA and intelligence community documents are under appeal or are awaiting declassification action.

* * * * *


Seeing nuclear proliferation as a major challenge to American power, John F. Kennedy firmly believed that the United States should use its influence to prevent Israel from going nuclear. The Dimona reactor had been discovered only two months before he assumed the presidency in January 1961 and Kennedy was already deeply concerned about Israel’s nuclear aspirations (for details see “Kennedy, Dimona and the Nuclear Proliferation Problem: 1961-1962” in National Security Archive Electronic Briefing Book No. 547). Those early concerns led to the first American inspection visit at Dimona, in mid-May 1961, and a subsequent face-to-face discussion between Kennedy and Israeli Prime Minister David Ben-Gurion on 30 May. The nuclear issue was also discussed in the meeting between Kennedy and Israeli Foreign Minister Golda Meir in late December 1962. Ben-Gurion explicitly assured Kennedy that Israel’s nuclear program was for peaceful purposes and Meir insisted that Israel was not on a path to develop nuclear weapons.

In early 1963 American concerns resurfaced. In January, Kennedy received a new National Intelligence Estimate (NIE) that highlighted the weapons potential of Dimona. It pointed out that the Dimona complex was likely to be operational later that year. According to the NIE, once Dimona was operating at full power, Israel might be on its way to produce enough plutonium for one or two weapons a year. Weeks later, in mid-March, Director of the Office of National Estimates Sherman Kent signed an intelligence estimate pointing out the negative consequences for the United States – at the regional and global levels – of Israeli acquisition of nuclear weapons. On 25 March, Kennedy met CIA Director John McCone to discuss the Israeli nuclear program, and soon afterwards asked National Security Advisor McGeorge Bundy to beef up U.S. intelligence collection capabilities aimed at both the Israeli nuclear program and Egypt’s “advanced weapons programs.” The next day Bundy issued National Security Action Memorandum (NSAM) 231, a formal directive to State, Defense, and CIA to study “Middle Eastern Nuclear Capabilities.”

By early April Kennedy and his advisers translated their concerns about Dimona into a quiet but affirmative policy demand: they insisted that Israel accept regular bi-annual U.S. inspections (or “visits,” as they were referred to in more diplomatic language), of Dimona. Initially, Kennedy applied the pressure through diplomatic messages. On 2 April, Ambassador to Israel Walworth Barbour presented to Ben-Gurion the U.S. request for semi-annual American visits; two days later, Israeli Ambassador Avraham Harman was summoned to the State Department for a similar message.

Ben-Gurion was expected to respond to Kennedy’s request on Dimona during his next meeting with Barbour, but he was not ready for a direct showdown with a determined U.S. president. Nor was he ready to accept Kennedy’s goal of semi-annual visits; that would have ended Dimona as the embodiment of Ben-Gurion’s existential insurance policy. Instead, he tried to avoid a confrontation by diverting Kennedy’s attention.

On 17 April 1963, an opportunity arose for doing so: Egypt, Syria, and Iraq signed the Arab Federation Proclamation, calling for a military union to bring about “the liberation of Palestine.” Such rhetoric was not new at the time, but Ben-Gurion used it to start an exchange with President Kennedy about Israel’s overall security predicament, while evading Kennedy’s specific Dimona request. Whether Ben-Gurion genuinely saw the Arab Federation Proclamation as an existential threat to Israel is unclear, but it tacitly justified Israel’s efforts to create a last resort option without the outright rejection of Kennedy’s request.

Ben-Gurion’s focus on a threat posed by the Arab Federation Proclamation vis-a-vis Kennedy’s focus on the danger of the Israeli nuclear project generated a remarkably discordant exchange of letters and personal oral messages between the two leaders throughout the spring of 1963. Ben-Gurion invoked the specter of “another Holocaust,” and insisted on Israel’s need to receive external security guarantees. But such an arrangement was not in the cards because Kennedy believed that so clear a sign of favoritism toward Israel would undermine U.S. relations with the Arab states.

Kennedy did not budge on Dimona and he was determined not to let Ben-Gurion change the conversation. He dismissed the prime minister’s alarm over the Arab Federation Proclamation as both nothing new and practically meaningless, and insisted that the real danger to the region was the introduction of advanced offensive systems, especially nuclear weapons. To address this concern Kennedy was willing to explore an arms control scheme that would cover both Israel and Egypt. It was evident, however, that his prime focus was halting the Israeli nuclear program.

In retrospect, this exchange amounted to a confrontation between the president of the United States and the prime ministers of Israel over the future of the Israeli nuclear program. The peak of that confrontation was Kennedy’s 15 June letter that Ambassador Barbour was supposed to deliver to Ben-Gurion the next day. The letter included detailed technical conditions under which Kennedy insisted that the biannual U.S. visits were to be conducted. The letter was akin to an ultimatum: if the U.S. government could not obtain “reliable information” on the state of the Dimona project, Washington’s “commitment to and support of Israel “could be “seriously jeopardized.” But the letter was never delivered to Ben-Gurion because on that day he stunned his country and the world by announcing his resignation.

Ambassador Barbour, who was prepared to deliver the letter, notified the State Department and asked for instructions. He recommended postponing delivery until the “cabinet problem is sorted out” and then addressing the letter to the next prime minister, a recommendation that Kennedy and his advisers followed.

On 5 July, less than ten days after Levi Eshkol became prime minister, Barbour delivered a 3-page letter to him from Kennedy. It was virtually the same as the 15 June letter to Ben-Gurion, accompanied with a few congratulatory lines to the new leader. Not since President Dwight Eisenhower's message to Ben Gurion, during the Suez crisis in November 1956, had an American president been so blunt with an Israeli prime minister. The specific demands that were presented to Ben-Gurion on how the U.S. inspection visits to Dimona should be executed remained word-for-word in the new letter. Many of Eshkol’s advisors saw the letter as a real ultimatum, a crisis in the making.[2]

Surprised by Kennedy’s tough demands on Dimona just days after taking office, Eshkol’s first response was to ask for more time for consultations. Only on 19 August, more than six weeks after he received the letter, did Eshkol come up with a response, which at times was vague. Under Kennedy’s pressure, Eshkol reluctantly assented, in principle, to allow regular visits by U.S. scientists to Dimona. Nevertheless, he did not agree to an early visit and avoided making a commitment to the bi-annual U.S. inspections that Kennedy sought.

The confrontation by letter between President Kennedy and two Israeli prime ministers resulted in a series of six annual U.S. inspections of the Dimona complex (1964-69), until President Richard Nixon ended them. (The first inspection in January 1964 may have been delayed because of Kennedy’s assassination.) While Lyndon Johnson was less eager to take the Israelis to task, he was concerned about nuclear proliferation and supported the inspections. Nevertheless, the Israelis made their nuclear weapons breakthrough during the 1960s regardless of the inspections, which evidently had little prohibitive or deterrent impact.


Part I U.S. Plans to Regularize Inspections of Dimona


[1] .  For the first full coverage of the issues and the Kennedy/Ben-Gurion/Eshkol correspondence, see Avner Cohen, Israel and the Bomb (New York: Columbia University Press, 1999), 115-174.

[2] .   The late Professor Yuval Ne’eman (1925-2006), who served  as the scientific director of the Soreq Nuclear Center, and  advised Prime Minister Eshkol on nuclear matters, referred to the demands of Kennedy’s letter as an ultimatum and described the exchange over Dimona as a crisis point. See Israel and the Bomb, 135.

[3] .  Avner Cohen notes in Israel and the Bomb, at page 404, note 51, that according to late journalist Moshe Zak (1918-2001), Ben-Gurion had already used similarly general language to describe his nuclear policy in various closed fora, for example in meeting with the chief editors of Israeli newspapers.

[4] .  Cohen, Israel and the Bomb, 122.

[5] .  Maurice Vaïsse, ed., Documents Diplomatiques Français 1963, Tome 1 (1er Janvier-30 Juin) (Paris: Imprimerie Nationale, 2000), 540-542.

[6] .  The French original:

Kennedy: C'est le même problème que Israël dont je voudrais que vous discutiez à fond avec le secretaire d’Ếtat, car c’est à l’heure actuelle un grave souci.

De Murville: Je suis entièrement d'accord avec vous sur ce point, mais les Israéliens pourraient tout au plus produire, un au deux détonateurs qui ne pourraient être considérés comme une véritable arme de guerre. Ceci entrainerant des troubles au Moyen-Onent, mais il n’y aurait pas là une veritable menace à la survie de l’espèce humaine

[7] .  The French original:

De Murville: Pour ce qui nous concerne, nous avons pris toutes les précautions nécessaires. Nous sommes engagés à leur fournir certaines quantités d'uranium pour leur réacteur, mais ils doivent nous le rendre dès qu'ils l’ont traité, de façon à ce qu'ils n'aient pas la possibilité d'en extraire Ie plutonium. Malheureusement. les Israéliens risquent de trouver ailleurs de l’uranium sans côntrole. C'est une question don’t je veux m'entretenir avec M. Rusk, car nous sommes d'accord avec vous sur le danger qui existe à ce sujet.

Kennedy: J'en suis heureux car, si Israël avait l'arme atomique, nous serions blames les uns comme les autres, vour pour avoir fourni de l'uranium, nous pour I'aide financière que nous donons à Israël. La position de ce pays est stupide, car ils donnent un prétexte aux Russes, qui sont en recul dans la région de nous mettre en accusation devant l'opinion publique, et peut- être pas sans raison.

[8] .  Ben-Gurion never explained in public what those “personal reasons” were. To this day there is an aura of mystery around Ben-Gurion’s final resignation. It is unknown what exactly pushed him to resign, whether it was one prime issue or a cluster of issues and to what extent it was a personal problem involving his state of mind. Some senior political leaders (e.g., Pinhas Sapir, Israel Galili) believed that Kennedy’s pressure on Dimona might have played a major role in his resignation decision, possibly because he realized that he had been trapped by his strategy toward Kennedy.  Others, including Yitzhak Navon, his senior aide (and later the president of Israel), dismissed the importance of the nuclear issue and referred to a cluster of personal and political problems that led to his resignation.  See Cohen, Israel and the Bomb, 134-36. Tom Segev, State at Any Price: The Story of Ben-Gurion’s Life [in Hebrew, Keter, 2017], 622-27.

[9] . As the AEC had preferred, the inspectors were not connected with the official safeguards program: two of them, Richard W. Cook and Ulysses M. Staebler, had been involved in reactor development, while the third, C. L. McClelland, was on the staff of the Arms Control and Disarmament Agency.

[10] .  Professor Ephraim Katchaslski Katzir was subsequently elected the fourth president of Israel (1973-1978.