Deep beneath the hills of central Iran, Tehran has ramped up its production of enriched uranium.
A recent report by the United Nations’ nuclear agency, the International Atomic Energy Agency (IAEA), said they were “seriously concerned” about the “significantly increased production and accumulation of highly enriched uranium”.
In 2018, as a deal brokered by Barack Obama that limited Iran’s nuclear programme in exchange for sanctions relief was ended by Donald Trump, Tehran had just 150kg of uranium enriched to 3.6 per cent. That number has now soared to 409kg of uranium enriched to 60 per cent.
Iran could convert this uranium into hundreds of kilograms of 90 per cent enriched, weapons-grade uranium in just a matter of weeks, according to analysis by the Washington, DC-based Institute for Science and International Security (ISIS).
That is enough for nine nuclear weapons.
Iran operates more than 30 facilities around the country that carry out different steps of the nuclear fuel cycle, many of which have been hit by the latest Israeli strikes, aimed at neutralising Iran’s possible nuclear threat.
But it is the most concerning of these plants, known as Fordow, that remains intact. It is buried deep underground and heavily fortified. It is also estimated to contain 2,700 centrifuges, vital for uranium enrichment.
Below, The Independent looks at what we know about the Fordow site on the outskirts of the city of Qom and why Israel is so concerned by it.
When was Fordow set up, and what is it?
Fordow is Iran’s second nuclear enrichment facility after Natanz, its main facility. From above, all that can be seen are five tunnels disappearing into a group of mountains inside a wide security perimeter.
In addition to being an estimated 80 meters under rock and soil, the site is reportedly protected by Iranian and Russian surface-to-air missile systems, though Israel may have already struck these weapons.
Though Fordow is smaller than Natanz, it has always been the main object of international concerns regarding Iran’s uranium-enrichment programme.
When Obama revealed the existence of the site in 2009, flanked by then French president Nicolas Sarkozy and British prime minister Gordon Brown, he described its size and configuration as “inconsistent with a peaceful program”.
Iran had told the IAEA just days before of its desire to build a new fuel enrichment facility, but by that point, the site had been under construction for years. The IAEA says they have imagery showing construction as far back as 2002.
Why is it key to the Israel-Iran conflict?
It is no coincidence that the first Israeli missiles to hit Iran in this latest exchange came shortly after an IAEA report expressed “serious concern” about Tehran’s uranium-enrichment programme.
“The significantly increased production and accumulation of highly enriched uranium by Iran, the only non-nuclear-weapon state to produce such nuclear material, is of serious concern,” the IAEA said in a 31 May report.
Weeks later, Israel’s ambassador to the United States, Yechiel Leiter, told Fox News that their entire aerial assault on Iran “has to be completed with the elimination of Fordow”.
Israeli prime minister Benjamin Netanyahu believes Iran’s uranium enrichment programme and the prospect of Tehran acquiring nuclear weapons poses an existential threat to Israel.
Several of Iran’s other nuclear facilities have already been hit, including two centrifuge production facilities on Wednesday morning.
Dozens of Iranian officials and nuclear scientists have also been assassinated.
Can Fordow be destroyed?
Herein lies Israel’s problem. Israel is one of the most heavily armed countries on the planet with some of the most sophisticated weapons. The air superiority it has established over Iran effectively gives the IDF free rein to bomb at will, but it lacks weapons that can penetrate a bunker as deep as Fordow.
In fact, experts believe there is only one weapon capable of damaging Fordow: the US-owned 30,000lb GBU-57/B Massive Ordinance Penetrator bomb.
Justin Bronk, a senior research fellow at the Royal United Services Institute (RUSI) and an expert in airpower, says the only means of destroying Fordow would be “with multiple impacts into the same hole”, using this US bomb.
What’s more, it can only be delivered, says Mr Bronk, by the US B-2 Spirit stealth bomber. Any successful operation would “rely on the weapons being delivered and functioning perfectly,” he adds.
So far, the US has not signalled an intentions to hit the nuclear site, and the Trump administration had been engaging Tehran in nuclear talks before Israel’s latest attacks. However, the US president has not ruled a strike.
US officials told CBS News that Trump is considering whether to join Israel in its attacks to stop the possibility of Iran enriching uranium to weapons-grade levels.
Speaking aboard Air Force One, the US President was clear-eyed about his red line: “Iran cannot have nuclear weapons. It’s very simple.”
Iran’s leader, Ali Khamenei, was equally forthright in his response. If the US get involved, Washington will face “serious, irreparable consequences”, he said.
