Today the National Security Archive publishes for the first time 30 recently declassified U.S. government documents disclosing the existence of a highly secret policy debate, during the first year of the Nixon administration, over the Israeli nuclear weapons program. Broadly speaking, the debate was over whether it was feasible--either politically or technically--for the Nixon administration to try to prevent Israel from crossing the nuclear threshold, or whether the U.S. should find some "ground rules" which would allow it to live with a nuclear Israel.

The documents published by the Archive are the primary sources for an article by Avner Cohen and William Burr, "Israel crosses the threshold," that appears in the May-June 2006 issue of the Bulletin of the Atomic Scientists. The article is now available on-line at the Bulletin's Web site. An edited version of the article will also appear in The Washington Post's Sunday "Outlook" section on April 30, 2006.

Among the key findings in the article:

* 1969 was a turning point in the U.S.-Israeli nuclear relationship. Israel already had a nuclear device by 1967, but it was not until 1968-1969 that U.S. officials concluded that an Israeli bomb was about to become a physical and political reality. U.S. government officials believed that Israel was reaching a state "whereby all the components for a weapon are at hand, awaiting only final assembly and testing."

* In the first months of the Nixon administration, senior officials such as Secretary of Defense Melvin Laird believed it was important that Washington try to check Israeli nuclear progress for the sake of stability in the Middle East.

* In April 1969 national security adviser Henry Kissinger issued National Security Study Memorandum (NSSM) 40 requesting the national security bureaucracy to develop options for dealing with the Israeli nuclear problem. A Senior Review Group (SRG), chaired by Henry Kissinger, was formed to deliberate and propose avenues for action to the President.

* The SRG outlined policy objectives to President Nixon and proposed initiating a probe with Israeli Ambassador Rabin designed to achieve those objectives. Nixon approved the SRG's proposal for action but declined to use deliveries of advanced F-4 Phantom jets as leverage for the probe. This decision was fateful for the entire exercise.

* On July 29, 1969 Ambassador Rabin was summoned by Acting Secretary of State Elliott Richardson and Deputy Secretary of Defense David Packard as the first step in the probe. The two officials pressed Rabin on three issues: (1) the meaning of Israel's "non-introduction" pledge; (2) Israel's signature on the NPT; (3) Israel's intentions on the missile issue. Rabin provided no replies and subsequently proposed to leave the whole issue for the meeting between President Nixon and Prime Minister Meir in late September.

* On the eve of Meir's visit the State Department prepared a background paper for the President concluding that "Israel might very well now have a nuclear bomb" and certainly "had the technical ability and material resources to produce weapons grade uranium for a number of weapons."

* No written record of the meeting between President Nixon and Prime Minister Meir on September 26 is available, but it was a key event in the emergence of the 1969 US-Israeli nuclear understanding. Subsequent documents suggest that Meir pledged to maintain nuclear restraint-no test, no declaration, no visibility-and after the meeting the Nixon White House decided to "stand down" on pressure on Israel.

* On October 7, 1969 Ambassador Rabin formally provided his belated answers to the US questions: Israel will not become a nuclear power; Israel will decide on the NPT after its election in November; Israel will not deploy strategic missiles until 1972.

* On February 23, 1970 Ambassador Rabin informed Kissinger that, in light of President Nixon's conversation with Meir in September 1969, Israel "has no intention to sign the NPT."

* Subsequently, the White House decided to end the secret annual U.S. visits to the Israeli nuclear facility at Dimona. Lower-level officials were not told of the decision and as late as May 1970 they were under the impression that the visits could be revived.

* By 1975, in keeping with the understanding with Israel, the State Department refused to tell Congress that it was certain that Israel had the bomb, even though U.S. intelligence was convinced that it did.

The newly declassified documents are from State Department records and Nixon Presidential Materials at the National Archives, College Park. They represent, however, only a small fraction of a large body of documents on NSSM 40 that remain classified. To elucidate the U.S. government debate over the issue of the Israeli bomb the National Security Archive has filed declassification requests for those key documents.