(SeaPRwire) –   The deaths of Iranian nuclear scientists in joint U.S.-Israeli military strikes have sparked concerns that should the Iranian government face destabilization, looser oversight of its uranium stockpiles and the spread of nuclear know-how could raise nuclear proliferation risks.

Though Iran is able to fill gaps left by its deceased personnel, experts note that recouping the lost specialized knowledge will be far more difficult, and unacknowledged nuclear sites across the country could also leave hazardous materials and sensitive expertise exposed to risk.

“At present, the risk of nuclear terrorism or nuclear materials ending up on the black market is still low,” stated Kelsey Davenport, nonproliferation policy director at the Arms Control Association.

“Non-state groups would encounter barriers to obtaining enriched uranium, and it is improbable that they possess the infrastructure needed to enrich it to weapons-grade purity and process it into the metallic form required for a warhead’s core,” she explained.

“That said, if the current Iranian government collapses or the ongoing conflict triggers severe domestic instability, the risk that nuclear materials could be stolen or rerouted to undeclared sites will rise.”

“There is an additional risk that Iranian nuclear scientists could choose to sell their specialized knowledge to countries or non-state groups that are pursuing nuclear weapons,” Davenport noted in a newly released report.

Multiple senior officials working within Iran’s nuclear and defense frameworks have been killed in the last two years, a timeline that aligns with the U.S. and Israeli strike campaign targeting Iranian nuclear facilities carried out between 2025 and 2026.

One of those killed is Hossein Jabal Amelian, head of the Organization of Defensive Innovation and Research (SPND), who died in 2026 during Operation Rising Lion and Operation Epic Fury.

The SPND is widely regarded as the successor to Iran’s pre-2004 nuclear weapons program, and it occupies a central role in the country’s newer weaponization research efforts.

Other individuals killed in 2025 are Mohammad Mehdi Tehranchi, Akbar Motallebizadeh and Said Borji, all of whom have ties to Iran’s weaponization work.

“The full effect of this strike campaign on Iran’s weaponization capacities is still not clear,” Jim Lamson, a senior research associate at the Center for Nonproliferation Studies, told Digital.

“New managers and scientists will be brought in to fill the empty positions, but the years of experience and specialized expertise the killed officials held will be nearly impossible to replace,” the former CIA analyst stated.

“A large number of leading scientists linked to suspected weaponization activities were killed between 2025 and 2026.”

“The people who take their places may also worry about being targeted in future attacks, either via military strikes or targeted assassinations. That concern could dampen their motivation and willingness to take part in any nuclear weapons development program.”

Lamson added that a large share of the targeted individuals worked in highly sensitive parts of Iran’s nuclear operations, including the nuclear fuel cycle and weaponization processes.

“These scientists held specialized knowledge in parts of the nuclear fuel cycle that are most relevant to nuclear weapons development, including the production of highly enriched uranium (HEU), which is Iran’s primary route to obtaining fissile material,” he noted.

“The scientists also possessed weaponization expertise, meaning they had deep knowledge of core elements involved in designing and manufacturing nuclear explosive devices,” Lamson added.

At the same time, targeted strikes carried out by the U.S. and Israel have also struck a network of facilities connected to their work, creating additional hurdles for Iran’s nuclear program in the short term, he explained.

“We have confirmed that no fewer than 11 sites linked to weaponization work have been struck since 2024,” Lamson stated.

“These sites include the SPND headquarters, a recently uncovered facility named Min-Zadayi located in northeastern Tehran, the SPND’s Taleghan and Sanjarian explosives testing grounds, the Defense Ministry’s Shahid Meisami complex in western Tehran, and multiple research universities.”

All of these facilities conducted work related to neutronics, explosives research, metallurgy and nuclear physics, all fields that are connected to nuclear weapons development, he said.

Even with the large scope of the most recent strikes, Iran still holds stockpiles of enriched nuclear material. On April 17, President Donald Trump announced that the U.S. would collaborate with Iran to retrieve “nuclear dust” — a reference to enriched uranium — from strike sites, noting that both nations would deploy heavy equipment to extract the material.

The International Atomic Energy Agency also estimates that Iran still possesses over 200 kilograms of uranium enriched to 60% purity at its Esfahan facility, an amount sufficient to build approximately five nuclear weapons if it undergoes further enrichment.

Iranian Foreign Minister Seyed Abbas Araghchi also stated that the material is still “trapped under the rubble” of earlier strike sites, and that Tehran has no intentions of retrieving it.

“It is entirely possible that Iran operates additional nuclear sites that have not been detected by the U.S. and Israel,” Lamson noted.

“We will need to wait and see to what extent these operations deliver a long-term strategic blow to Iran’s capacity to develop nuclear weapons.”

“It is straightforward to tally the damage and casualties caused by the U.S. and Israeli strikes, but far more difficult to gauge their real effect on Iran’s capacity and willingness to develop a nuclear weapon,” Lamson clarified.