Israel Claims Killing of Iranian Nuclear Scientists Sets Program Back ‘Years,’ But Experts Warn Knowledge Can’t Be Bombed Away

Israel says it has dealt a devastating blow to Iran’s nuclear program by killing at least 14 of its top scientists in a campaign of targeted strikes — a rare direct assault on the intellectual core of Tehran’s nuclear ambitions. But nuclear experts and European officials warn the damage is likely to be temporary and far from irreversible.

In an interview with The Associated Press, Israel’s ambassador to France, Joshua Zarka, said the scientists’ deaths — combined with two weeks of Israeli airstrikes and U.S. bunker-busting bombs — have pushed Iran’s nuclear efforts back significantly.

“The fact that the whole group disappeared is basically throwing back the program by a number of years, by quite a number of years,” Zarka said. “It’s almost impossible now to build weapons from what may have survived.”

The Scientists Behind the Program

According to Zarka, those killed included physicists, engineers, chemists, and explosives experts — many of them possessing decades of accumulated expertise. Nine were killed in the first wave of Israeli strikes on June 13, with Iran confirming the death of another prominent scientist, Mohammad Reza Sedighi Saber, this week. Saber had survived an earlier Israeli attack that killed his 17-year-old son.

“These people weren’t targeted just because they knew physics,” Zarka said. “They were actively involved in building a nuclear weapon.”

Analysts Disagree: ‘Knowledge Cannot Be Erased’

Despite Israel’s claims, international nuclear analysts say Iran retains the intellectual and scientific foundation to rebuild.

“You can bomb facilities, you can kill scientists, but the knowledge base remains,” said Mark Fitzpatrick, a former U.S. diplomat and now an analyst with the International Institute for Strategic Studies. “They have substitutes — maybe not as senior, but capable.”

European governments have echoed this view, warning that military action alone can’t eliminate a state’s nuclear know-how.

“Strikes cannot destroy the knowledge Iran has acquired over several decades,” UK Foreign Secretary David Lammy told Parliament. “Nor any regime ambition to deploy that knowledge.”

Iran insists its nuclear program is peaceful, and U.S. intelligence agencies currently assess that Tehran is not actively pursuing a nuclear weapon. However, Israel has long contended that Iran could weaponize its nuclear material rapidly if it chose to.

Deterrence or Provocation?

Pavel Podvig, a Geneva-based expert on nuclear weapons, believes the targeted killings were meant as psychological warfare as much as strategic disruption.

“Killing scientists may be intended to scare others from joining these programs,” he said. “But it’s a very slippery slope. What’s next — students studying physics?”

Zarka seemed to confirm the deterrence angle: “People asked to join a future nuclear weapon program will think twice,” he said.

A History of Assassinations

Israel has long been suspected of assassinating Iranian scientists, though it rarely claims responsibility. This campaign marks a shift — direct, open acknowledgment. Iran’s most senior nuclear scientist, Mohsen Fakhrizadeh, was killed in 2020 in an ambush Iran blamed on Israel.

Analyst Lova Rinel, of France’s Foundation for Strategic Research, says such operations may delay, but don’t halt, nuclear ambitions. “It’s more symbolic than strategic,” she said. “The program survives.”

Zarka disagreed, arguing that repeated sabotage and assassinations have steadily undermined Iran’s progress: “Iran would have had a bomb long ago without these setbacks.”

The Legal Grey Zone

Targeting scientists raises legal and ethical questions. Under international humanitarian law, deliberate killing of civilians and non-combatants is banned — but scholars say legality depends on the targets’ roles.

“If the scientists were actively participating in hostilities or working for the military, they might be lawful targets,” said Emory Law School’s Laurie Blank. “But without full intelligence, it’s impossible to know.”

Johns Hopkins professor Steven R. David defended Israel’s actions. “These scientists were working for a regime that threatens Israel’s existence. That makes them legitimate targets,” he said.

Knowledge Is Harder to Kill

Ultimately, experts agree that while Israel’s campaign may have slowed Iran’s nuclear progress, it hasn’t eliminated the threat. Technical knowledge and nuclear blueprints remain. The timeline may have changed, but the capability endures.

“Turning uranium into a warhead isn’t simple,” Zarka concluded. “But these people had the know-how — and that’s why they were eliminated.”