A spokesman for the Iranian Atomic Energy Agency said Monday that the country’s security authorities knew the cause of the explosion, but would not provide details and “security considerations” for the time being. Other Iranian officials have publicly suggested that the US or Israeli activists are to blame, although neither country has acknowledged involvement in the incident.
A Middle East security official said in an interview that the damage was caused by a “huge explosive device”
“There was an opportunity and someone in Israel calculated the risk and seized the opportunity,” said the official. He described the building as “completely destroyed”.
Other analysts and nuclear experts also said the evidence so far strongly suggests that a bomb detonated inside the facility, known as the Iran Centrifuge Assembly Center. In addition to satellite images, photos by the Iranian atomic energy organization show doors that have been broken by hinges, cracked walls and missing roof panels.
“The simplest explanation is an explosion inside the building,” said Jeffrey Lewis, a professor and weapons expert at the Middlebury Institute of International Studies in Monterey, California. “It will be really difficult to see this as an accident.”
The building was commissioned in 2018 as the main Iranian center for the assembly of new centrifuge machines for the large uranium enrichment plant in the same complex south of Tehran. Iran was allowed to operate the facility under the terms of the 2015 Iranian Atomic Energy Agreement, and the site was visited by inspectors from the International Atomic Energy Agency, the UN nuclear watchdog. The Iranian plant in Natanz produces low-enriched uranium, which is used in commercial nuclear power plants to generate electricity. Additional processing could potentially transform the uranium into weapons-grade fuel for atomic bombs.
The Middle East security official said the explosion was a “wake-up call” designed to deter Iran after months of threatening advances in that country’s nuclear program. The activists who carried out the apparent attack clearly had a remarkable penetration of the Iranian nuclear program and detailed knowledge of the facility, he said.
“Doing this takes some serious preparation and time,” he said.
Regardless of whether it was sabotage, the explosion was a setback for Iran’s nuclear efforts. Nevertheless, the analysts did not agree on the extent of the damage.
It will undoubtedly take Iran many months to rebuild the facility, which means long delays in installing the advanced high-performance centrifuges that Iran has built in recent years, said David Albright, nuclear weapons expert and president of the Institute for Science and International Security, a nonprofit organization in Washington that researches nuclear weapons programs. “The assembly plant can be a bottleneck,” said Albright. “It will definitely delay you.”
However, other analysts said the explosion would have little immediate impact on Iran’s two existing uranium enrichment facilities. Ultimately, the attack could encourage Iran to conduct nuclear activities in secret and not in publicly-declared facilities that are subject to international inspection, several experts said.
“As the Iran Agreement continues to collapse under external pressure, it will be much easier for those who want to get out of the nuclear deal to build more secret facilities – and eventually a bomb,” said Lewis. “You can reset them for a few months, but is it really worth it if you don’t have a plan to solve the nuclear problem in those few months?”
In Israel, military and intelligence agencies were typically silent about the attack and any role the country could have played. Several ex-security officials who did not claim inside knowledge searched published pictures and media reports and found reason to be impressed by the sophistication and effectiveness of the strike.
Former Israeli deputy national security advisor Chuck Freilich found that if part of the operation, a cyberattack took place after Iran tightened its defense after previous network attacks. These included the recent alleged hacks by Iran and Israel on each other’s public infrastructure and the Stuxnet virus, which badly damaged Iran’s nuclear program a decade ago.
“They have been on high alert ever since,” said Freilich. “If this was a cyberattack and someone got through, it really shows top skill.”
Retired General Yaakov Amidror, former head of intelligence research for the Israel Defense Forces, welcomed the attack as a necessary check on Iran’s ongoing progress towards nuclear and strategic weapons capabilities. Amidror, a critic of the Iranian nuclear deal, said the deal gave Tehran the freedom to strengthen its expertise in two particularly threatening areas: refining centrifuges and improving long-range missile technologies. The latest attacks on both programs, he noted.
Hendrix reported from Jerusalem. Louisa Loveluck in London contributed to this report.