Israeli nuclear program
The State of Israel conducts a nuclear program, including both activities under inspection of the International Atomic Energy Agency, and what is widely accepted to be a nuclear weapons arsenal. Israel is not a signatory to the Treaty on the Non-Proliferation of Nuclear Weapons and maintains a policy of strategic ambiguity about its capabilities.
The main development facility is at Dimona, and the main Jericho base is Zeharya, near the city of Bet Shemesh.
In a U.S. Air Force Counterproliferation Center paper, COL Warner Farr divides the Israeli program into three phases:
- 1948-1962: With French Cooperation
- 1963-1973: Independent development of basic weapons
- 1974-forward: "The Bomb in the Basement": reduction in strategic ambiguity
Research began in 1949, in the chemistry division of the Weizmann Institute of Science, under Ernst David Bergmann. Early projects included exploration for uranium in the Negev Desert, heavy water preparation, and uranium extraction.
David Ben-Gurion secretly created the Israeli Atomic Energy Commission (IAEC) in 1952, headed by Bergmann. IAEC began cooperation with French and Norwegian counterparts. Ben-Gurion had become Defense Minister, for a second time, in 1955, and apparently decided to begin a nuclear weapons production program. 
While there had always been French cooperation, it accelerated in 1956, as a quid pro quo for Israel's support of Britain and France in the Suez operation.
Previously unreported British cooperation in 1958 provided 20 tons of heavy water, without any monitoring of its use. The BBC said the sale decision appeared to have been made by civil servants in the Foreign Office and the UK Atomic Energy Authority, with no consultation with ministers in the government of Harold Macmillan. Britain did not tell the U.S. about the transaction, and rejected a second Israeli request in 1961. 
Rupture with France
The program matures
After the 1973 Arab-Israeli War, it was well accepted by the superpowers that Israel had a competent nuclear arsenal. Israeli strategic policy began to move beyond pure final deterrence.
Bomb in the Basement
"Bringing the bomb out of the basement" is a term coined by Louis Beres, to describe changes in their nuclear posture, in which they move closer and closer to disclosing nuclear status rather than maintaining ambiguity. A new range of missions emerged beyond the final deterrent "Samson Option":
- To deter a large conventional attack,
- To deter all levels of unconventional (chemical, biological, nuclear) attacks,
- To preempt enemy nuclear attacks,
- To support conventional preemption against enemy nuclear assets,
- To support conventional preemption against enemy non-nuclear (conventional, chemical, biological) assets,
- For nuclear warfighting,
- The “Samson Option” (last resort destruction)/
In the 1990s, there was more and more discussion of the Israeli need for weapons not used in their wars -- although the declared nuclear powers also have fought wars without nuclear weapons but still consider them necessary. Avner Cohen write: “It [Israel] must be in a position to threaten another Hiroshima to prevent another holocaust.” Shimon Peres, in July 1998, was quoted in the Jordan Times as saying, “We have built a nuclear option, not in order to have a Hiroshima, but to have an Oslo,” referring to the peace process.
Developments in the Iranian nuclear program have been posed both as Iranian balances to Israel, and Israeli rationales to use nuclear weapons against deeply buried nuclear targets. Even with aggressive Iranian development, however, Israel presumably has enough weapons to retaliate massively for any Iranian attack. It is also agreed, however, that only a few delivered weapons would devastate the population and industrial centers of Israel.
U.S. intelligence probably started monitoring Israeli nuclear activity in 1956; a weapons program was not assumed. While Bergmann was asked about the work, it was assumed, in 1958, that it was related to the Soreq research facility, which made heavy water and worked on peaceful projects. Within the next two years, however, U.S. and British intelligence began to suspect, and then became near-certain, of movement toward producing bomb-grade fissionable materials. The head of the Israeli weapons industry, RAFAEL, resigned in May 1959, and was rumored to be related to opposition to a nuclear weapons program; this was not confirmed.
In June of the same year, the Norwegian foreign ministry told a U.S. Atomic Energy Commission (AEC) representative about heavy water sales to Israel, but this information was not disseminated for 18 months. Central Intelligence Agency clandestine sources learned independently of the sale. In June 1960, the U.S. Embassy informally asked Israel about activity in the Negev, they were told it was a "textile plant". They reported to Washington, in August, that a "major reactor with French assistance" was underway. Israel said, in September, that Dimona was a "metallurgical research institute." U.S military attaches took pictures, from the ground, in 1960, and concluded it was probably a reactor.
First internal U.S. reporting
After debriefing Professor Henry Gomberg of the University of Michigan, who consulted to the the Israeli Atomic Energy Commission (IAEC) and reported his conclusion to the U.S. Ambassador to Israel, Ogden Reid and to the representative of the AEC in Paris. In early December 1960, the CIA issued a report on the well-developed Dimona military facility. Secretary of State Christian Herter formally asked Israel about its intentions on December 7. The Israeli ambassador to the U.S., Avraham Harman, said he did not know what it was and would obtain "urgent advice." On December 20, the New York Times reported on Harman's response that the facility was a peaceful 24-megawatt research reactor, rather than the reactor the U.S. suspected was in the 100 to 300 megawatt range.
The U.S. intelligence committee was directed to do a "post-mortem" on why it had taken so long to discover the program. 
In 1968, Edward Teller had discussions with Carl Duckett, then Deputy Director of Central Intelligence for Science and Technology, which led to the basic United States intelligence community assumptions about the Israeli nuclear program.
Perhaps the most definitive information, however, came not from any external collection, but from an Israeli technician, Mordechai Vanunu, who took pictures inside Dimona and released them in 1986.
Weapons and doctrine
Most estimates suggest that the country has in the range of 100 to 200 nuclear weapons, primarily for Jericho series ballistic missiles, but also gravity bombs and possibly for submarine-launched cruise missiles.
Some estimates go as high as 400 warheads, with a total yield of 50 megatgons.
There have been reports of nuclear artillery projectiles for 175mm guns and 203mm howitzers, both cannon that were retired from U.S. service. The U.S. later retired the 155mm nuclear shells for its standard M109 howitzer, which Israel does have in its inventory. Artillery-launched nuclear warheads have been retired, in favor of longer-range guided missiles, by all declared powers; it is probable that Israel has done so as well.
- Warner D. Farr (September 1999), The Third Temple's Holy Of Holies: Israel's Nuclear Weapons, U.S. Air Force Counterproliferation Center
- Jeffrey Richelson (2006), Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea, W.W. Norton, ISBN 9780394053838, pp. 237-238
- Inigo Gilmore (23 December 2001), "Israel reveals secrets of how it gained bomb", Telegraph
- Michael Crick (3 August 2005), "How Britain helped Israel get the bomb", BBC
- Anthony Cordesman, Perilous Prospects: The Peace Process and the Arab-Israeli Military Balance, Westview Press, 1996, p. 118, quoted by Farr
- Beres, Louis Rene, “Israel's Bomb in the Basement: A revisiting of `Deliberate Ambiguity' vs. `Disclosure', Between War and Peace: Dilemmas of Israeli Security, edited by Efraim Harsh (London, England: Frank Cass, 1996), 113-133, quoted by Farr
- Cohen, Avner and Miller, Marvin, Nuclear Shadows in the Middle East: Prospects for Arms Control in the Wake of the Gulf Crisis (Cambridge, Massachusetts: Massachusetts Institute of Technology, 1990), p. 18, cited by Farr
- Richelson, pp. 249-251
- Central Intelligence Information Report: Nuclear Engineering Training/Large Nuclear and Electrical Plant near Beersheba/French Nuclear Assistance to Israel/Israeli Attitude toward the Announcement of its Large-Scale Nuclear Program/Opportunity for US Participation in Nuclear Powered Water Conversion, National Security Archive, George Washington University
- Dimona Revealed, National Security Archive, George Washington University
- Post-Mortem on SNIE 100-8-60: Implications of the Acquisition by Israel of a Nuclear Weapons Capability, National Security Archive, George Washington University
- Israel profile: Nuclear Chronology 1960-1969, Nuclear Threat Initiative
- "Mordechai Vanunu: The Sunday Times articles", Sunday Times (UK), 21 April 2004
- Nuclear Weapons, Federation of American Scientists
- Report No. 2001/10: Nuclear Weapons Proliferation, Canadian Security Intelligence Service, 25 February 2002