William Burr, National Security Archive, and Avner Cohen, James Martin Center for Nonproliferation Studies, editors 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 at the Monterey institute of International Studies (MIIS). The U.S. government learned about the facts of the sale through Canadian intelligence and found out even more from its Embassy in Argentina. 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.
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 for 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.
That Argentina made the yellowcake sale to Israel has already 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 September 1964 when U.S. Embassy sources in Argentina confirmed the sale to Israel.
- The Israelis evaded answering questions about the transaction. When U.S. scientists visited the Dimona facility in March 1966 as part of the August 1963 secret agreement between Presiden Kenned and PrimeMinister Eshkol, 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.
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 were concerned about stability in the Middle East, which the Israeli nuclear program could threaten. Both wanted yellowcake sales safeguarded to curb the Israeli nuclear program and the spread of nuclear weapons capabilities worldwide.
According to the initial Canadian information-as well as additional details later gleaned by the U.S. State Department-in late 1963 Argentina had secretly negotiated a long-term contract with Israel to provide at least 80 tons of yellowcake. While the Americans and the British were initially somewhat skeptical about the accuracy of the Canadian report, subsequent investigations demonstrated that it was correct. Trying to ensure that uranium exports were safeguarded to prevent diversion into military programs, Washington complained to the Argentines about the unsafeguarded sale, then queried the Israelis, and applied intelligence resources to find out more about the transaction.
Washington found that the sale was irreversible and that it could learn nothing about its purpose, although it kept trying. The Argentines said they could only apply strong safeguards to future sales while the Israelis evaded all queries about the yellowcake, although as part of a high-level deal between President Kennedy and Prime Minister Eshkol from 1963 Israel had allowed U.S. government experts to visit their nuclear reactor at Dimona. The U.S. team apparently raised the Argentine yellowcake during a 1966 visit but the Israelis were not helpful in providing explanations. The CIA could not learn anything concrete about the transaction either.
As the United States, the United Kingdom and Canada had routinely acted with the utmost discretion when sharing 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.
Israel's interest in uranium is as old as the state itself. As early as 1949-50, Israel started with a geological survey of the Negev to determine whether and to what extent uranium could be extracted from the phosphates deposits there. Throughout the 1950s and early 1960s Israel explored the viability of the phosphates option, some pilots plants were built, but finally it was determined that it would be too costly. Israel, therefore, had to find uranium from overseas sources.
For the Dimona project the Israelis initially had gotten uranium from France, but in the early 1960s Paris began to restrict the supply and Israel sought to diversify its sources by securing uranium from Argentina, South Africa and elsewhere. Conversely, because the United States was worried about the Israeli nuclear program and its implications for stability in the region, it made efforts to monitor closely Israeli purchases of nuclear material and investigated the Argentine-Israeli deal. While Washington was then exploring ways to establish a global safeguards system to regulate nuclear supplies through the International Atomic Energy Agency (IAEA), nothing yet was available with any teeth, such as the future Nuclear Suppliers Group, to check such sales, much less restrict the Israeli nuclear program.
Early on when American, British, and Canadian intelligence tried to uncover the secrets of the Israeli nuclear program, they clearly understood that Israel needed a reprocessing facility to transform its spent reactor fuel into weapons-grade plutonium. For example, according to an October 1964 National Intelligence Estimate on nuclear proliferation a "major deficiency, in terms of a weapons program, is the lack of a plutonium separation plant." Although the Israelis had told both the US and Canada that the Dimona facility would include a pilot plant for reprocessing, the widespread assumption was that it was probably too small to produce enough plutonium for a weapons program. That the original French design for Dimona included a large underground reprocessing facility (Machon 2) was one of Israel's deepest nuclear secrets, which Mordecai Vanunu later revealed. To this day, it is unclear exactly how much Western intelligence knew about the facility and exactly when and how it learned it.
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.