Israel had been involved in nuclear research since the country's inception. With French assistance that began about 1957, Israel constructed a natural uranium research reactor that went into operation at Dimona, in the Negev Desert in 1964. Dimona's operations were conducted in secret, and it was not brought under international inspection. According to a 1982 UN study, Israel could have produced enough weapons-grade plutonium at Dimona for a number of explosive devices. Under an agreement with the United States in 1955, a research reactor also was established at Nahal Soreq, west of Beersheba. This reactor was placed under United States and subsequently International Atomic Energy Agency (IAEA) inspection. The Nahal Soreq facility was not suspected of involvement in a weapons program.

American and other Western specialists considered it possible that Israel had developed a nuclear weapons capability incorporating enriched uranium as an alternative to plutonium. The United States suspected that up to 100 kilograms of enriched uranium missing from a facility at Apollo, Pennsylvania, had been taken in a conspiracy between the plant's managers and the Israeli government. In 1968, 200 tons of ore that disappeared from a ship in the Mediterranean probably were also diverted to Israel. Foreign experts found indications that Israel was pursuing research in a laser enrichment process although no firm evidence had been adduced that Israel had achieved a capability to enrich uranium. In a 1974 analysis, the United States Central Intelligence Agency (CIA) expressed the belief that Israel had already produced nuclear weapons. Among the factors leading to this conclusion were the two incidents of disappearance of enriched uranium and Israel's costly investment in the Jericho missile system.

Officially, Israel neither acknowledged nor denied that nuclear weapons were being produced. The government held to the unvarying formulation that "Israel will not be the first to introduce nuclear weapons into the Middle East." As of 1988, Israel had not acceded to the Treaty on the Non-Proliferation of Nuclear Weapons (1968). It was, however, a party to the Treaty Banning Nuclear Weapons Tests in the Atmosphere, in Outer Space, and Under Water (1963). There was no evidence that Israel had ever carried out a nuclear test, although some observers speculated that a suspected nuclear explosion in the southern Indian Ocean in 1979 was a joint South African-Israeli test.

In 1986 descriptions and photographs were published in the London Sunday Times of a purported underground bomb factory. The photographs were taken by a dismissed Israeli nuclear technician, Mordechai Vanunu. His information led experts to conclude that Israel had a stockpile of 100 to 200 nuclear devices, a far greater nuclear capability than had been previously estimated.

A nuclear attack directed against targets almost anywhere in the Middle East would be well within Israel's capacities. Fighter-bombers of the Israeli air force could be adapted to carry nuclear bombs with little difficulty. The Jericho missile, 202 , developed in the late 1960s, was believed to have achieved a range of 450 kilometers. An advanced version, the Jericho II, with a range of nearly 1,500 kilometers, was reported to have been testflown in 1987.

Data as of December 1988