Unlock Editor’s Digest Lock for Free
FT editor Roula Khalaf will select your favorite stories in this weekly newsletter.
The United States has struck three Iranian nuclear sites to ensure that the Islamic Republic will no longer be able to enrich nuclear material.
Air attacks targeted vast, sophisticated research and centrifugal arrays accumulated by Iran, sometimes secretly and sometimes fully documented by international inspectors.
The extent of the damage remains unknown, but it will undoubtedly set back decades of investment in nuclear enrichment technology. Meanwhile, Israel has already killed many of Iran’s leading nuclear scientists, trying to erase the knowledge and expertise that built these plants.
It is not entirely known whether Iran is moving or hiding thousands of kilograms of nuclear fuel that it has enriched in recent years. This included an international UN inspector on May 31 that nearly weapons grade (approximately 60% purity) could be rapidly concentrated.
Fordow Fuel Concentration Plant
The most reinforced Iranian nuclear site, Fordow, is buried under the rocks and wrapped in reinforced concrete, designed to be safe from any of Israeli traditional weapons.
So the US had to use the GBU-57 E/B Massive Ordnance Peretator, the world’s most powerful nuclear-free bomb, or some of the MOPs, the GBU-57 E/B Massive Ordnance Peretator, or the MOP.
It’s also the most secret. Its very existence was unknown to Western intelligence agencies until 2008, and was made public in 2009 by US President Barack Obama.
The Western Intelligencead’s assessment was that a row of Fordow’s spinning centrifuges could be used to enrich nuclear fuels to increasingly high concentrations from Iran’s peaceful nuclear energy program.
During the JCPOA contract with the world powers that began in 2015, Fordow was reclassified as a research facility, with regular surprise visits from UN inspectors. These visits continued until recently, with the IAEA rating that Fordow was not used in the weapons program.
The JCPOA was an agreement with the UN Security Council and five permanent members of Germany and Germany that require Iran to keep it at less than 4% in exchange for sanctions relief.
After President Donald Trump abandoned the JCPOA in 2018, inspectors were still granted access, and recently documented changes to the plant’s design.
Natanz Enrichment Complex
The Natantz Enrichment Facility is Iran’s largest nuclear enrichment facility. Israel had attacked twice a few weeks ago before Saturday’s US attack.
The US has spent years with Israel trying to slow Iran’s progress on enrichment technology, including cyberattacks, known as the “Olympic Games.” These tasks hindered progress for several years.
The site features thousands of underground centrifuges designed to produce various grades of enriched uranium, as well as on-ground research facilities that Iran uses to test new centrifugal designs. Everything was completely under UN inspection.
The Israeli attack could have caused significant centrifugal damage, perhaps if Israeli fighters were operating when they knocked out electricity to the plants.
What remained was seen as a formidable challenge to destroy as a Fordow. According to the IAEA, Israeli attacks have so far only hit several facilities on the ground.
Isfahan Nuclear Technology Center
The oldest Isfahan site of Iran’s established nuclear research centres has been in operation since the early 1980s. It was built in cooperation with China after the Islamic Revolution in 1979.
At least 3,000 scientists and engineers worked at the site, but no major enrichment was undertaken at the facility, according to UN inspectors.
However, the tranche of the document stolen and published by the Mossad in 2018 shows that until 2003, when Iran publicly shelved its formal nuclear weapons program, Isfahan scientists were involved in the more complicated task of creating feasible bombs.
There is no publicly available evidence that this study continued after 2003.

Where are other nuclear facilities in Iran?
Iran has several other nuclear facilities across the country, but the biggest and most important are the Bucher Nuclear Power Plant and the Bandar Abbas Uranium Production Factory.
Although explosions have been reported near Bush in recent weeks, it is not clear whether the facility was directly attacked by Israeli fighter jets. The radiation level is not jumping. It shows that Israel may be trying to damage the infrastructure around the plants, not the reactor itself.
On June 12, Mohammad Eslami, head of Iran’s atomic energy organization, said Iran had completed construction of its third enrichment facility in a secret location.
“The new site is fully built and in a safe and immortal place,” he said. According to the semi-official Mehr news agency. “As soon as the centrifuge is installed and set up, the concentration will begin.”
By satellite map Aditi Bhandari