Mordechai Vanunu, The Former Nuclear Technician Who Revealed Israel’s Nuclear Secrets

Published January 9, 2026

In 1986, Mordechai Vanunu leaked details about Israel's top-secret nuclear program to the British press. He was later found guilty of treason and sentenced to 18 years in prison.

Mordechai Vanunu

Right LivelihoodAfter working at an Israeli nuclear facility, Mordechai Vanunu told the world about his country’s nuclear secrets.

Israel has long followed a policy of “strategic ambiguity,” when it comes to its nuclear program, refusing to disclose whether or not it has nuclear weapons. But in 1986, a former nuclear technician named Mordechai Vanunu stepped forward — and exposed Israel’s nuclear program to the world.

He shared what he knew with the British press, which published Vanunu’s assertion that Israel had quietly produced hundreds of nuclear weapons. Almost immediately afterward, Vanunu was lured to Rome by a “honeypot” spy. There, where he was abducted by Israeli intelligence agents and brought back to Israel to stand trial.

Mordechai Vanunu was ultimately found guilty of treason and sentenced to 18 years in prison. In the years since, some have come to see him as a noble whistleblower, while others consider him a traitor to his country.

The Man Who Documented Israel’s Nuclear Capabilities

Born to a large Jewish family in 1954, Mordechai Vanunu spent his early years in Marrakech, Morocco. But in 1963, his family emigrated to Israel.

After attending school, Vanunu spent three years serving with the Israeli Defence Force, during which he fought in the Yom Kippur War. Upon the completion of his service, he received an honorable discharge and went to work as a nuclear technician at Israel’s top-secret Dimona nuclear research center in 1976. There, Israel was quietly developing nuclear weapons.

While working at Dimona, Vanunu also began to study philosophy at Ben Gurion University. His studies changed his life. As The Guardian noted in 2004, he began to question Israel’s policies, support Palestinians, and work with an organization called the Movement for the Advancement of Peace.

Dimona Nuclear Factory

Public DomainThe Dimona nuclear facility was top secret – and Israel refused to admit whether it had nuclear weapons.

Vanunu also began to question the secrecy around Israel’s growing nuclear program. He began to feel that he had an obligation to share the extent of the country’s nuclear capabilities with his countrymen and the wider world. And when Vanunu learned he was going to be fired in 1985 after nine years on the job, he started taking photographs of the facility.

Soon afterward, Mordechai Vanunu left the country — and made the decision to reveal Israel’s nuclear secrets to the British press.

How Mordechai Vanunu Exposed Israel’s Nuclear Program

With a $7,500 severance payoff in his pocket, Mordechai Vanunu traveled the world, visiting Nepal, Burma, and Thailand before stopping off in Australia. There, he converted to Christianity, and church discussions around peace and nuclear proliferation convinced him to share what he knew about Israel’s nuclear program with a freelance journalist.

The journalist shopped the story around, and found an audience for it with London’s Sunday Times. Vanunu flew to the United Kingdom, where he shared his photos and inside knowledge about the Dimona nuclear plant.

On Oct. 5, 1986, the Sunday Times published its explosive exposé based on Vanunu’s intel, entitled “Revealed: The Secrets of Israel’s Nuclear Arsenal.”

In the shocking article, journalist Peter Hounam wrote: “Hidden beneath the Negev desert, the factory has been producing atomic warheads for the last 20 years. Now it has almost certainly begun manufacturing thermonuclear weapons, with yields big enough to destroy entire cities.”

Revealed Nuclear Secrets Article

The Sunday TimesThe Sunday Times published Vanunu’s story as an exposé in 1986.

Indeed, the Sunday Times reported that Israel’s nuclear program was so advanced that it ranked as the world’s sixth nuclear power, and that the country had an estimated 200 weapons. With that, Israel’s policy of “strategic ambiguity” around its nuclear program was seriously challenged.

And it didn’t take long for Israel to react.

In fact, Israel had been tipped off about the story before it was published and on orders from prime minister Shimon Peres, the country’s spy agency Mossad launched an operation to arrest Vanunu. Though they failed to stop the publication of Vanunu’s story, the spy agency did succeed in luring Vanunu out of London with the use of a “honeypot” spy named Cindy.

The Capture of Mordechai Vanunu In Rome

According to reporting from Haaretz in 2004, Mordechai Vanunu thought he’d run into Cindy entirely by chance. The two crossed paths while looking at the same store window in Leicester Square and it was Vanunu, not the agent, who spoke first. Vanunu asked her if she were a tourist, and the agent responded that she was a Jewish-American visiting London.

Vanunu asked her out for coffee, and the two seemingly hit it off. Before long, Cindy invited Vanunu to Rome. Vanunu agreed – even though Hounam warned him that Cindy might be a Mossad agent.

Ultimately, it turned out that Hounam was right. Moments after Vanunu entered Cindy’s “sister’s” apartment in Rome, two Mossad agents seized him, drugged him, and brought him back to Israel.

Mordechai Vanunu Arrested

Sharir Efi/The National Library of IsraelMordechai Vanunu was abducted in Rome and brought back to Israel to stand trial.

“It was luck, pure luck, that we managed to track him down, establish contact with him, and bring him to Israel in the end,” a retired Mossad official told Haaretz.

Mordechai Vanunu went on trial for espionage and treason in August 1987. He was ultimately sentenced to 18 years in prison, 11 of which he spent in solitary confinement in a six-by-nine-foot prison cell

Traitor Or Whistleblower?

In the aftermath of Mordechai Vanunu’s arrest, trial, and sentencing, many in the global community sided with him, declaring him to be a whistleblower and hero for peace. The Bertrand Russell Peace Foundation nominated Vanunu for the Nobel peace prize in 1988, and a petition from 20 scientists, including 12 Nobel prize winners, declared: “No greater regard can be shown by the court for the decent opinion of humankind than by acknowledging the lonely courage of Mordechai Vanunu.”

But many in Israel saw Vanunu as a traitor.

Mordechai Vanunu Close Up

Wikimedia CommonsMordechai Vanunu spent 11 years in solitary confinement, triggering calls for his release from organizations like Amnesty International.

So why did Mordechai Vanunu reveal his country’s nuclear program? In 2004, after serving his sentence, Vanunu explained his motives to the BBC. “I felt it was not about betraying; it was about reporting,” he said. “It was about saving Israel from a new holocaust.”

Vanunu also denies that his whistleblowing was an attempt to end Israel’s nuclear program. “What I did was to inform the world what is going on in secret; I didn’t come and say, we should destroy Israel, we should destroy Dimona. I said, look what they [Israel] have and make your judgement.”

The Israeli government disagreed, and Mordechai Vanunu is under severe restrictions to this day: He cannot meet with foreigners or leave the country. Deputy Prime Minister Joseph Lapid said in 2004, “We think he still knows secrets and we don’t want him to sell them again. We think there are things he knows that he hasn’t divulged yet. He may do so; he’s hell-bent to harm this country, he hates this country.”

But Mordechai Vanunu would not change history if he could.

“I have no regrets in spite of the fact I have paid a heavy punishment,” Vanunu remarked. “I think it was worth it.”


After reading about Mordechai Vanunu, the man who exposed Israel’s nuclear program to the world, learn about Operation Wrath of God, the Mossad’s revenge for the Munich Massacre of 1972. Then, learn about how Operation Entebbe rescued over 100 hostages after a plane hijacking.

author
Genevieve Carlton
author
Genevieve Carlton earned a Ph.D in history from Northwestern University with a focus on early modern Europe and the history of science and medicine before becoming a history professor at the University of Louisville. In addition to scholarly publications with top presses, she has written for Atlas Obscura and Ranker.
editor
Kaleena Fraga
editor
A senior staff writer for All That's Interesting since 2021 and co-host of the History Uncovered Podcast, Kaleena Fraga graduated with a dual degree in American History and French Language and Literature from Oberlin College. She previously ran the presidential history blog History First, and has had work published in The Washington Post, Gastro Obscura, and elsewhere. She has published more than 1,200 pieces on topics including history and archaeology. She is based in Brooklyn, New York.
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Carlton, Genevieve. "Mordechai Vanunu, The Former Nuclear Technician Who Revealed Israel’s Nuclear Secrets." AllThatsInteresting.com, January 9, 2026, https://allthatsinteresting.com/mordechai-vanunu. Accessed January 10, 2026.