Could US attack Iran’s Fordow nuclear site? Military movements offer a clue
Refuelling aircraft were tracked heading east, potentially to support B-2 jets carrying bunker-buster bombs
The US has stepped up its military presence in the Middle East since the weekend but has left certain details vague to preserve operational ambiguity for Donald Trump as he considers whether the US will intervene in the Israel-Iran war.
Critically, there has been no new information about the deployment of B-2 bombers that would be used to attack Iran’s deep-lying nuclear enrichment site at Fordow with 13.6-tonne (30,000lb) bunker-buster bombs, designed to penetrate 60 metres of rock.
On Monday night, the US defence secretary, Pete Hegseth, said he had “directed the deployment of additional capabilities” to US Central Command in the Middle East, an exercise he said was “to enhance our defensive posture in the region”.
Donald Trump, meanwhile, told reporters he was looking for “a real end” to the conflict as the US president returned to Washington having cut short his trip to the G7 summit in Canada. “I’m not looking for a ceasefire, we’re looking at better than a ceasefire,” he said, without being more specific.
However, clues that the Pentagon is considering a long-range air raid came from the movement of more than 31 US Air Force refuelling aircraft. The planes, mostly KC-135 Stratotankers and KC-46 Pegasuses, were tracked by AirNav Systems, a flight-tracking website, as they headed east towards Europe on Sunday. There were further reports of some planes flying further east on Tuesday.
US Air Force B-2 bombers have a long range, of about 6,000 miles without refuelling, but they usually operate from a limited number of bases: Whiteman in Missouri, Fairford in Oxfordshire and most notably the isolated base of Diego Garcia in the south Indian Ocean, now leased from Mauritius by the UK for the US.
B-2 bombers attacked five underground Houthi weapon facilities from Whiteman, 8,000 miles away, last October. Diego Garcia is far closer to Fordow, a 3,200-mile trip each way, which would require refuelling on the return leg once a bombing run on Iran’s nuclear sites had been completed.
Only the US is considered to have a bomb large enough – the GBU 57/B Massive Ordnance Penetrator – to possibly destroy Fordow, one of Iran’s two main uranium enrichment sites, estimated to be 80-90 metres below a mountain. The only plane certified to carry the 6-metre weapon is the B-2.
At one point in the middle of the last decade, the US was thought to have only 20 of the bombs, its largest non-nuclear weapon, but more recent estimates are higher.
Though Israel appears to have achieved dominance over Iran’s skies since it launched its attack on the country on Friday, it attacked Fordow on only the first day of the operation. The IAEA nuclear watchdog said on Monday that no damage to the enrichment plant had been seen.
Justin Bronk, an aviation expert with the Royal United Services Institute thinktank, said “multiple impacts” would almost certainly be required to destroy Fordow, “with the second bomb impacting inside the hole made by the first”.
Though a B-2 can carry two bunker-busting bombs, a serious assault by the US designed to eliminate the facility would probably require the deployment of more than one bomber. Bronk said: “An attack would require redundancy since the weapons have to function and be delivered perfectly to get down into the facility and explode at the right depth to cause critical damage.”
Satellite imagery in May showed the presence of six B-2 bombers at Diego Garcia, about half the total number considered operational at any one time – the US has a total of 19 – but there has not been any more recent reporting. Several companies supplying commercial satellite imaging also work for the US government.
According to a 2019 article in the New York Times, at some point a decade before, the US Pentagon constructed a replica of Fordow and test-bombed it with a 30,000lb device. A highly classified video of the attack was later shown by Leon Panetta, a defence secretary under Barack Obama’s presidency, to the Israeli politician Ehud Barak. “The bomb destroyed the mock-up in the desert,” the newspaper reported.
The US may also consider attacking Iran’s other nuclear enrichment site, at Natanz. Though a smaller overground site was destroyed by bombing on Friday, a facility somewhere between 8 and 12 metres underground is said by the IAEA to be relatively undamaged, though the Israeli military has disputed this.
An important question for the White House and the Pentagon is whether they believe, after five days of airstrikes by Israel, that there is any threat to US jets operating over Iran. But there is no shortage of military assets available if the US wants to mount an expanded attack targeting any remaining air defence and missile launch sites.
A second aircraft carrier strike group, led by the USS Nimitz was sent from east Asia towards the Middle East earlier this week, where it will join the USS Carl Vinson carrier, which is already operating relatively close to Iran, around the Arabian Sea. At least three US destroyers are now also in the eastern Mediterranean.