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Mohsen Fakhrizadeh’s body was carried through the streets of Tehran, Iran.

Iranian Defense Ministry via AP

Assassination of top Iran weapons scientist dims hopes for nuclear diplomacy

The assassination earlier today of a prominent scientist who led Iran’s clandestine nuclear weapons R&D could chill prospects for reinvigorating a 2015 agreement impeding Iran’s paths to an atomic bomb in exchange for economic concessions.

Physicist Mohsen Fakhrizadeh was slain in an attack on a highway outside of Tehran, according to Iranian news reports, which blamed Israel. International Atomic Energy Agency (IAEA) documents show Fakhrizadeh headed the AMAD program, a secret nuclear weapons effort that Iranian officials shuttered at the end of 2003. Documents Israeli agents spirited out of Iran in 2018 suggest some clandestine weapons work continued under Fakhrizadeh in a Revolutionary Guard research unit established in 2011.

In probing Iran’s past nuclear activities, IAEA had long sought to interview Fakhrizadeh. “He’s one of the very few individuals fingered by name in IAEA reports,” says Naysan Rafati, a senior Iran analyst at the International Crisis Group. He held “vast institutional knowledge of Iran’s past nuclear weapons program and its ongoing R&D activities,” adds Andrea Stricker, a nonproliferation analyst at the nonprofit Foundation for Defense of Democracies. Iran refused to make Fakhrizadeh available to IAEA, claiming he was merely an academic at Imam Hussein University, where he held a teaching position. Few details about his nuclear expertise are publicly available, but his reputation among Iran watchers is outsize; he’s often referred to as Iran’s J. Robert Oppenheimer, who led the Manhattan Project in the United States during World War II.

“Terrorists murdered an eminent Iranian scientist today,” Iran’s foreign minister, Javad Zarif, tweeted. “This cowardice—with serious indications of Israeli role—shows desperate warmongering of perpetrators.” “Such perpetrators have no conscience and are void of empathy,” adds Ali Akbar Salehi, president of the Atomic Energy Organization of Iran. The assassination follows a July explosion at an advanced centrifuge facility at Iran’s Natanz nuclear site, which Iran labeled an act of sabotage.

If Fakhrizadeh wanted Iran to build a bomb, his ‘martyrdom’ at the hands of a foreign power will make that outcome far more likely.

Jeffrey Lewis, Middlebury Institute of International Studies at Monterey

Neither blow is likely to deal more than a tactical setback to Iran’s nuclear ambitions, analysts say. A decade ago, five scientists linked to Iran’s nuclear program were assassinated in a campaign attributed to Israeli intelligence. In a subsequent interview with Science, Salehi asserted that the loss of the scientists, who are known in Iran as “nuclear martyrs” and whose framed photos hang in his office in Tehran, did not impede Iran’s nuclear activities. Rather, he said, the killings prompted students in other fields to switch to nuclear science. Salehi told Science today that Iran intends to carry on Fakhrizadeh’s work. “Thanks to his efforts,” Salehi says, “an efficient system has been established which is able to pursue the envisioned projects without any hindrance.”

“No one wants a colleague to have died in vain. No one wants to buckle under foreign pressure,” says Jeffrey Lewis, director of the East Asia Nonproliferation Project at the Middlebury Institute of International Studies at Monterey. “If Fakhrizadeh wanted Iran to build a bomb, his ‘martyrdom’ at the hands of a foreign power will make that outcome far more likely.”

U.S. President-elect Joe Biden has expressed a desire to revive the Iran nuclear deal, a multilateral pact that has gradually unraveled after the current U.S. administration pulled out in May 2018. Iran has since breached the pact by expanding R&D on advanced centrifuges for enriching uranium. The country has steadily ratcheted up enrichment and has now accumulated about 12 times as much enriched uranium as the agreement permits.

Iran’s actions in the coming days may well determine the nuclear pact’s fate. “It’s a bit of a high wire act,” says Rafati, who presumes Iran had hoped to lie low before Biden’s inauguration. Stricker predicts a muted Iranian response, via its proxies. “Iran needs [the nuclear deal] for economic relief more than it wants to lash out and start a military conflict over the loss of Fakhrizadeh,” she says. Lewis, however, sees the assassination as a grave blow. “This will harden attitudes in Tehran and complicate any effort by the Biden administration to revive the nuclear deal,” he says.