HOW MUCH DID AMERICA´S BOMBS DAMAGE IRAN´S NUCLEAR PROGRAM? / THE ECONOMIST

Obliterated or simply obscured? 

How much did America’s bombs damage Iran’s nuclear programme?

Assessments vary wildly and it is impossible to know for sure

People walk past a mural depicting Iranian missiles in Tehran, Iran / Photograph: Arash Khamooshi/The New York Times/Redux/eyevine

“OPERATION MIDNIGHT HAMMER”, as America called its strike on Iran on June 22nd, was a vast raid involving more than 125 military aircraft. 

It was the largest-ever strike by B-2 stealth bombers and the first use in battle of the GBU-57, America’s largest bunker-buster bomb. 

Seven bombers flew east over the Atlantic from Whiteman air-force base in Missouri on the 37-hour mission to Iran and back, helped by in-flight refuelling tankers and fighter jets to sweep the skies ahead of them. 

Decoy planes flew west over the Pacific to confuse anyone watching air deployments. 

Dozens of Tomahawk cruise missiles were also fired at Iran from submarines. 

The operation’s scope and scale would “take the breath away” of most observers, boasted Pete Hegseth, the defence secretary. 

But how much damage did it actually do to Iran’s nuclear programme?

Donald Trump declared that the three facilities targeted had been “totally obliterated”. 

But on June 25th several American media outlets published details of a much more sceptical take from the Defence Intelligence Agency (DIA), which reportedly concluded that the American and Israeli strikes set Iran’s nuclear programme back by months, rather than years. 

The centrifuges Iran uses to isolate the uranium isotope needed for bomb-making were largely “intact” and the country maintained other secret facilities that “remain operational”, according to CNN’s account of the report. 

“Much” of Iran’s stockpile of near-weapons-grade uranium had been moved before the strikes and so remains intact, the New York Times relayed. 

To quell the ensuing uproar, both Tulsi Gabbard, the director national intelligence, and John Ratcliffe, the head of the Central Intelligence Agency, issued statements insisting the targeted sites had been “destroyed”.

Boom or bust?

The B-2s dropped 14 GBU-57s on buried nuclear sites at Natanz and especially Fordow, which Mr Trump described as the “primary” target. 

The Tomahawks struck Isfahan, a complex of facilities where Iran turns uranium metal into a gaseous compound and back, makes centrifuges and may have stored much of its stock of highly enriched uranium (HEU), meaning it has a high proportion of the fissile isotope. 

The UN’s International Atomic Energy Agency (IAEA) estimates that Iran had 400kg of uranium of 60% purity, a short hop to weapons-grade (usually 90%). 

That would be enough for ten bombs.

Before the strikes Western officials disagreed about whether even the GBU-57, or “massive ordnance penetrator” (MOP), would do much damage to Fordow’s deeply buried chambers. 

It can burrow through 60 metres of ordinary concrete, but only a lesser depth of reinforced concrete. 

Repeatedly striking the same spot allows it to penetrate deeper. 

Satellite images of Fordow released by Maxar, an American firm, after the bombing raid show a series of craters on the mountainside.

David Albright, a former IAEA inspector who now leads the Institute for Science and International Security, a think-tank in Washington, argued prior to the war that Fordow was “more vulnerable than people realise”. 

Israel had detailed knowledge of the building’s designs, he noted, including knowledge of the tunnels: “where they start, how they zig and zag, where the ventilation system is, the power supplies”. 

The site had only one ventilation shaft; destroying that, he argued, could put Fordow out of action for “a few years rather than a few months”. 

Moreover, even if the bombs did not demolish all of the Fordow complex, the powerful blasts might nonetheless have damaged or destroyed much of the machinery inside.

There are other reasons to question the DIA’s pessimism. 

Its analysts themselves labelled their report “low-confidence”, meaning that its credibility is “questionable”, it is “poorly corroborated”, or there are “significant concerns” with the source. 

It is reportedly based solely on satellite images and intercepted communications. 

As new information comes in, American spies’ assessment is likely to change. 

On June 24th Mr Albright noted that new evidence, which arrived after the completion of the DIA’s report, suggested that “more enriched uranium stocks are in the rubble than believed just yesterday”. 

He says that Iran is likely to have lost close to 20,000 centrifuges at Natanz and Fordow, creating a “major bottleneck” in any renewed effort to build a bomb.

Fordow was originally a secret project, revealed by Western countries in 2009. 

The question now is whether Iran has other intact secret facilities and a sufficient stock of HEU hidden away with which to restart the programme away from prying eyes. 

Iran has threatened to withdraw from the Nuclear Non-Proliferation Treaty. 

If it does so, IAEA inspectors would have no way to observe Iran’s future nuclear work. 

Nevertheless, Israel’s spies have displayed an extraordinary ability to penetrate Iran’s nuclear enterprise and security forces, and have repeatedly assassinated nuclear scientists and generals.

The Iranian project has been much more extensive and dispersed than the efforts of Iraq and Syria, whose reactors Israel bombed in 1981 and 2007 respectively. 

“Will this look more like Syria 2007—where a nuclear programme was decisively ended—or Iraq 1981, where nuclear ambitions were strengthened, and repeated intervention was required?” asks Nicholas Miller, a non-proliferation expert at Dartmouth College. 

“Assuming the current regime stays in power in Iran, my money is on the latter.”