The Israel-Argentina Yellowcake Connection

1 July 2013 — The National Security Archive

Previously Secret Documents Show That Canadian Intelligence Discovered That Israel Purchased Yellowcake from Argentines during 1963-1964

Information Later Shared with British and Americans, Who Accepted It after Hesitation

U.S. State Department Insisted that Uranium Sales Required Safeguards to Assure Peaceful Use but Israel Was Uncooperative and Evasive About the Yellowcake’s Ultimate Use

National Security Archive Electronic Briefing Book No. 432

Posted — June 25, 2013

For more information contact:
William Burr — 202/994-7000 or
Avner Cohen — 831/647-6437 or 202/489-6282 (cell);

Washington, D.C., June 25, 2013 — During 1963-64, the Israeli government secretly acquired 80-100 tons of Argentine uranium oxide (“yellowcake”) for its nuclear weapons program, according to U.S. and British archival documents published today for the first time jointly by the National Security Archive, the Nuclear Proliferation International History Project, and the James Martin Center for Nonproliferation Studies. The U.S. government learned about the sale through Canadian intelligence and found out even more from its Embassy in Argentina. Washington was concerned that the yellowcake purchase cast doubts on Israel’s claims about a peaceful nuclear program. In response to U.S. diplomatic queries about the sale, the government of Israel was evasive in its replies and gave no answers to the U.S.’s questions about the transaction.

The U.S. government learned about the facts of the sale through Canadian intelligence and found out even more from its Embassy in Argentina. The government of Israel avoided giving answers to any questions about the yellowcake purchase.

These nearly unknown documents shed light on  one of the most obscure aspects of Israel’s nuclear history–how secretly and vigorously Israel sought raw materials for its nuclear program and how persistently it tried to cultivate relations with certain nuclear suppliers. Yellowcake, a processed uranium ore, was critically important to Israel for fuelling its nuclear reactor at Dimona and thereby producing plutonium for weapons. The story of the Argentine yellowcake sale to Israel has remained largely unknown in part because Israel has gone to great lengths to keep tight secrecy to this day about how and where it acquired raw materials for its nuclear program. Moreover, the U.S. government and its close allies kept secret for years what they knew at the time.

That Argentina made the yellowcake sale to Israel has been disclosed in declassified U.S. intelligence estimates, but how and when Washington learned about the sale and how it reacted to it can now be learned from largely untapped archival sources. Among the disclosures in today’s publication:

* French restrictions on Israel’s supply of uranium in 1963 made U.S. and British officials suspect that Israel would attempt to acquire yellowcake from other sources without any tangible restrictions to sustain its nuclear weapons program.

* A Canadian intelligence report from March 1964 asserted Israel had all of the “prerequisites for commencing a modest nuclear weapons development project.”

* When the Canadians discovered the Argentine-Israeli deal they were initially reluctant to share the intelligence with Washington because the United States had refused to provide them with information on a recent U.S. inspection visit by U.S. scientists to Dimona.

* U.S. and British intelligence were skeptical of the Canadian finding until the U.S. Embassy sources in Argentina confirmed the sale to Israel.

* The Israelis would not answer questions about the transaction. When U.S. scientists visited the Dimona facility in March 1965 to check whether the Israelis were meeting peaceful uses commitments, they asked about the yellowcake but their Israeli hosts said that question was for “higher officials.”

* In 1964 U.S. officials tried to persuade the Argentines to apply strong safeguards to future uranium exports but had little traction for securing agreement.

* In 1965, while the CIA and the State Department were investigating the Argentine yellowcake sale, Washington pursued rumors that the French uranium mining company in Gabon had sought permission to sell yellowcake to Israel.

Since late 1960 when the CIA learned that the Israelis had been constructing, with French assistance, a nuclear reactor near Dimona in the Negev Desert, the United States and close allies (and the Soviet Union as well) worried that Israel had a nuclear weapons program under way. The Canadian government was also concerned; sometime in the spring of 1964 its intelligence agency learned about the yellowcake sale and shared the information with the British.

Convinced that the Canadian information confirmed Israel’s interest in nuclear weapons, a British diplomat calculated that the yellowcake would enable the Israelis to use their Dimona nuclear reactor to produce enough plutonium for its first nuclear weapon within 20 months. In light of these concerns, the British shared the information with the U.S. government; both governments, as well as Canada, were concerned about stability in the Middle East, which the Israeli nuclear program could threaten. Both Washington and London wanted yellowcake sales  safeguarded to curb the spread of nuclear weapons capabilities to other countries.

As the United States, the United Kingdom and Canada always had done in the past with intelligence information about the Israeli nuclear program, they kept the entire yellowcake sale secret. On this matter there were no leaks; the issue never reached the U.S. media then or later.

The documents in today’s publication are from the U.S. and the British National Archives. All of the  U.S. documents were declassified in the mid-1990s but have lingered in a relatively obscure folder in the State Department’s central foreign policy files at the U.S. National Archives. They may never have been displayed in public before as the file appeared to be previously untouched.  A few of the British documents have been cited by other historians, including ourselves, but the fascinating story of British-Canadian-United States intelligence cooperation and coordination has also been buried in relative obscurity.  The juxtaposition of U.S. and British records makes a fuller account possible, although some elements of the story remain secret, such as the identity of the Canadian intelligence source on the yellowcake purchase.  Only Israeli and Argentine documents, however, can provide the full story of the yellowcake sale.

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THE NATIONAL SECURITY ARCHIVE is an independent non-governmental research institute and library located at The George Washington University in Washington, D.C. The Archive collects and publishes declassified documents acquired through the Freedom of Information Act (FOIA). A tax-exempt public charity, the Archive receives no U.S. government funding; its budget is supported by publication royalties and donations from foundations and individuals.

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