In the lead-up to the 1967 Six Day War, Israel hid a plutonium core in an old British-built police station outside the town of Gedera, with plans to turn it into a functioning nuclear bomb if necessary, according to testimony from a former Israeli official who guarded the site, which was published Wednesday.

The article was published as part of a new series on the nuclear aspect of the Six Day War in the Nonproliferation Review, a journal run by the Middlebury Institute of International Studies that describes itself as focusing on the “causes and consequences of the spread of weapons of mass destruction.”

The testimony of Elie Geisler, the former atomic official, was collected by Avner Cohen, one of the premier researchers of Israel’s nuclear history. Cohen is a contentious figure within Israel, as much of his writings deal with Israel’s alleged nuclear weapons, which is at odds with the Israeli government’s stance of ambiguity — neither confirming nor denying the existence of such capabilities.

Get The Times of Israel's Daily Edition by email and never miss our top stories Free Sign Up

In the article series, Cohen delves deeper into his belief that Israel sought to create and potentially detonate a nuclear bomb during the war if necessary as a show of strength against the attacking Arab armies. This view is not universally accepted among scholars of the war.

Cohen’s assessment is based largely on interviews he conducted in 1999 and 2000 with Col. (res.) Yitzhak Yaakov, who oversaw the military’s weapons program and claimed to have been behind the plan. The interviews were not published until 2017, four years after Yaakov’s death, to coincide with the 50th anniversary of the war.

These nuclear plans were “the last secret of the 1967 war,” Cohen told The New York Times in 2017, when he released Yaakov’s interview transcripts.

According to Cohen, this view is further supported by this new testimony, in which Geisler recounts his role in defending what he says was one of the few plutonium cores in Israel’s possession at the time.

“During my inspections, I reflected on the fact that I had under my control the first Jewish, Israeli nuclear core,” he wrote.

In his testimony — parts of which were published in a book under a pseudonym in 2017 — Geisler describes a mini-civil war that nearly took place at the site, as Col. Yaakov demanded access to the technically civil-run facility.

Due to an apparent mix-up, his permission to enter the site never arrived, and a standoff ensued — Yaakov backed by IDF cadets and Geisler by a contingent of border guards.

Geisler recalled telling Yaakov that “if he tried to use force, we would unnecessarily spill Israeli blood.” To avoid violence, Geisler called one of his superiors, which would normally amount to a breach of protocol, and was told that they “knew about Colonel Yaakov and his visit, but for some reason — someone forgot or something else — had not informed me.”

According to Cohen, Geisler’s account matched a claim made by Yaakov in his 1999 interview that “there was some problem” in gaining access to the site.

Geisler apparently believes that Yaakov’s attempt to enter the site amounted to “an illegitimate effort by the IDF to claim custody over the nation’s nuclear weapons,” according to Cohen.

“I just happened to be there and was an eyewitness to events, some of which I understood their powerful historical footprint, and some I did not. This is why it took me several decades before I could put these memories to paper,” Geisler told Cohen, who compiled the account into one cohesive article from multiple interviews and conversations.

However, Cohen disputes this view, saying he believes that Yaakov’s actions were not an attempted military coup, but rather derived from real confusion and unclear organizational structure, “genuine growing pains of Israel’s abrupt, improvisational entry into the nuclear age.”

‘The package’

From 1963 to 1973, Geisler worked in Israel’s nuclear program as part of the classified Scientific Authority, a civil organization responsible for the country’s weapons development efforts, according to the testimony.

In the weeks preceding the war, Geisler was sent with a contingent of border guards to the British Mandate-era Qatra police station outside Gedera and tasked with guarding a “package,” a wooden crate containing a radioactive “metallic half-sphere.”

“My primary job was to take care of the ‘package’ by using Geiger and other counters to verify the safety and security of the object — the core — and to ascertain that no radiation leakage was present,” Geisler wrote.

As the device released both gamma and alpha radiation, he was convinced that this was the “real thing,” a plutonium core.

Geisler believes that at that time, Israel would have only had enough radioactive material to create one or two cores, though some have claimed two or three were produced.

“I would stand in this small room and stare at the object with much awe, having seen photos and movies of the devastation of Hiroshima and Nagasaki,” he said.

“I knew perfectly well that the use of the device would be the ‘last resort’ of the political leadership of the country, whose policy was, and remains to this day, not to be the first to introduce nuclear weapons to the Middle East, neither confirming nor denying the Israeli nuclear-weapon capability,” Geisler added.

He developed contingency plans with the commander of the border guards for how they could move the core “to an assembly point, where it would join with the remainder of the device.”

According to Cohen, in his interviews in 1999 and 2000, Yaakov detailed the plan to detonate such a device, which was code-named “Shimshon,” or Samson, after the biblical character.

Yaakov said this plan derived from deep fear.

“Look, it was so natural,” Yaakov told Cohen. “You’ve got an enemy, and he says he’s going to throw you to the sea. You believe him.”

“How can you stop him?” he asked. “You scare him. If you’ve got something you can scare him with, you scare him.”

According to the Yaakov, the plan would see Israel “scare” Egypt by detonating an atomic device on a mountaintop site about 12 miles from an Egyptian military complex at Abu Ageila.

“The plan, if activated by order of the prime minister and military chief of staff, was to send a small paratrooper force to divert the Egyptian army in the desert area so that a team could lay preparations for the atomic blast,” the report said.

“Two large helicopters were to land, deliver the nuclear device and then create a command post in a mountain creek or canyon. If the order came to detonate, the blinding flash and mushroom cloud would have been seen throughout the Sinai and Negev deserts, and perhaps as far away as Cairo.”

As it turned out, Israel’s victory was swift and decisive and there was no need for any doomsday plan, but Yaakov still believed Israel should have gone ahead with it and openly declared its nuclear prowess.

In 2001, some two years after his conversations with Cohen, Yaakov was arrested in Israel and charged with passing secret information with intent to harm state security. Though it was not detailed in the indictment, this offense was tied to a memoir that Yaakov had written.

He was acquitted of the main charge but found guilty of the unauthorized handing over of secret information. Yaakov received a two-year suspended sentence.

Times of Israel staff contributed to this report.