Israel successfully assassinated 19 senior Iranian nuclear scientists during the 12-Day War, depriving Tehran’s atomic "weapons program of its most capable and experienced personnel," according to a new intelligence assessment by a leading nonproliferation organization.
The military campaign evaporated decades of nuclear know-how, striking at the heart of Tehran’s weapons program in a way kinetic attacks could not, according to the Institute for Science and International Security.
"This act weakened Iran’s base for building nuclear weapons, eliminating needed expertise and hard-to-get management experience," the organization determined. "This time the Israeli effort is different, and recovering may be far more difficult and take far longer."
The report comes as American and Israeli intelligence agencies work to assess the physical damage at Iran’s top three nuclear sites, including the mountain bunker at Fordow. While an initial classified report by the Defense Intelligence Agency suggested only "moderate damage" to Tehran’s uranium enrichment sites, the findings were quickly discredited as "low confidence" and based on Iranian propaganda. Fresh assessments indicate that American bunker buster bombs "badly damaged, and potentially destroyed" Fordow while two other facilities "were destroyed and could take years to rebuild," according to the New York Times.
The question now is whether Iran has the personnel capable of rebuilding these complex facilities and conducting the scientific work necessary to assemble a functional bomb. The institute’s assessment suggests Iran is facing an uphill battle, particularly as Israel continues to threaten the country’s remaining nuclear scientists.
"In a highly secretive program such as Iran’s nuclear weapons program, highly cognizant of the risk of leaks, it is likely that full knowledge of the most sensitive, most current developments of the program and how individual parts were intended to work together existed only in the heads of a few," the report states. "Those Iranians who choose to work on producing nuclear weapons in the future will possess less information and expertise, while facing increased personal risks, resulting in an overall notably greater challenge in building the weapon itself."
The 19 scientists whom both Israel and Iran confirmed to be dead possessed nuclear knowledge spanning decades, much of which centered on explosives, nuclear coding, and ballistic missiles.
Six of the scientists have expertise in "explosives or multipoint initiation of explosives," according to the institute. At least three were top exports in "nuclear coding or simulation relevant to nuclear weapons development." Another four were highly trained in "neutron initiators," a critical component in nuclear weapons, and two were linked to Tehran’s effort to procure foreign technology needed to power a bomb.
Four additional scientists were experts in the "diagnostics associated with testing components of nuclear weapons," while seven others had "experience working on ballistic missiles," gas centrifuges, and "nuclear propulsion for submarines."
The average age of those scientists killed was 60, suggesting that Israel targeted the most experienced crop of engineers. At least 3 of the 11 Israel identified received their doctorate degrees in Russia, though most others received them in Iran.
Among those killed was nuclear physicist Fereydoun Abbasi-Davani, a central figure in Iran’s nuclear weapons industry. Born in 1958, he joined Iran’s Islamic Revolutionary Guard Corps shortly after the hardline regime’s 1979 revolution.
When the Islamic Republic began its clandestine nuclear weapons program in the 1990s, Abbasi-Davani worked to "design, develop, and test the neutron initiator, made of uranium deuteride, producing neutrons through deuterium-deuterium fusion. This device is placed at the center of the weapon-grade uranium core of Iran’s nuclear weapon to introduce a spurt of neutrons at the right time to start the chain reaction." The U.S. government sanctioned him in 2012 over his work on nuclear technology.
Mohammad Mehdi Tehranchi, another leading Iranian scientist, was a central figure in Tehran’s Amad Plan, a secretive nuclear weapons program that ended in 2003 after being discovered by the international community. As the president of Iran’s Islamic Azad University, Tehranchi served as a key link between Tehran’s civilian and military nuclear programs, helping to secure "overseas illicit procurements," according to the institute.
"Both Abbasi-Davani and Tehranchi played senior roles in sculpting and carrying out Iran’s post-Amad nuclear weapons efforts," working together to obfuscate the military dimensions of their work and mislead the international community, the report states.
Israel also eliminated Ali Bakui Katrimi, who "specialized in the development of multipoint initiation systems (MPI), nuclear weapons design, and explosives technologies." Another key scientist, Abdolhamid Minouchehr, had decades of experience in "reactor physics, nuclear simulation, and advanced nuclear fuels."
Ahmadreza Zolfaghari Daryani, meanwhile, was one of the "few Iranian experts in nuclear bomb yield calculations," with a knowledge-base the institute says will be difficult to replace.
Israeli intelligence operatives reportedly phoned several Iranian commanders shortly after the war started, warning them to flee the country or be assassinated along with their wives and children. As the institute’s report explains, the Jewish state made similar threats to top Iranian scientists.
"In an apparent effort to pre-empt recovery and recruitments, Israel threatened a far larger group of scientists during the war via social media, an effort that may continue, warning them explicitly that death awaits them if they work on nuclear weapons," the institute noted. Israel also offered "rewards and safety" to informants who step forward with information about Iran’s efforts to reconstitute the nuclear program.
"The desired message is clear: Any Iranian scientist or engineer who decides to work on nuclear weapons or on secret gas centrifuge programs will know that his or her life, and potentially their family’s lives, are at risk and that a colleague nearby could become an informant, exposing the entire secret effort, with potentially devastating consequences," according to the report.
In addition to taking out the leading minds behind Iran’s nuclear weapons work, Israel successfully destroyed its technological blueprints, including a copy of the Nuclear Archive that was located in the basement of Tehran’s Organization of Defensive Innovation and Research, or SPND. Other Israeli operations during the war "destroyed or severely damaged a range of nuclear weaponization development and production facilities, likely laden with sensitive equipment and data."