Why Donald Trump is hesitant to strike Iran's Fordow: Role of US B-2 bombers, ‘bunker buster' bombs explained

Mint

5 hours ago

US President Donald Trump has conveyed to defence officials that any military strike on Iran's deeply buried uranium enrichment facility at Fordow would only make sense if the so-called 'bunker buster' bomb—the GBU-57 Massive Ordnance Penetrator (MOP)—could be guaranteed to destroy the target.
The GBU-57, a colossal 13.6-tonne (30,000-pound) bomb, is designed to penetrate hardened underground facilities, and Pentagon experts have assured Trump that dropping these bombs would effectively eliminate Fordow.
However, Trump remains unconvinced and has delayed authorising any strikes on Iran, instead waiting to see if the threat of US military involvement might bring Iran back to the negotiating table.
The debate over the GBU-57's effectiveness has been a contentious issue within the Pentagon since Donald Trump's term began.
Defence officials briefed on the matter have expressed doubts that even multiple conventional GBU-57 bombs could fully penetrate and destroy Iran's Fordow, which Israeli intelligence estimates to be buried as deep as 300 feet (approximately 90 metres) beneath a mountain.
According to the Defence Threat Reduction Agency (DTRA), conventional bombs might only collapse tunnels and bury the facility under rubble rather than completely neutralise it.
Some officials believe that only a tactical nuclear weapon could guarantee the destruction of Fordow, but US President Trump has explicitly ruled out the use of nuclear arms, and such options were not presented to him by Defence Secretary Pete Hegseth or Chairman of the Joint Chiefs of Staff General Dan Caine during White House briefings.
The briefing further revealed that a possible strategy to destroy Fordow would involve first 'softening' the ground with conventional bombs before deploying a tactical nuclear weapon from a B-2 stealth bomber to obliterate the entire site, reports Guardian.
This scenario, however, remains off the table given Trump's firm stance against nuclear use.
The GBU-57, tested extensively by the DTRA, remains the largest conventional bomb in the US arsenal capable of penetrating fortified underground targets, but its limitations against deeply buried sites like Fordow have raised serious concerns.
When questioned by reporters about the possibility of striking Iran's nuclear facilities, Donald Trump was deliberately ambiguous, stating, 'I can't say that … You don't seriously think I'm going to answer that question.'
He added, 'You don't know that I'm going to even do it. You don't know. I may do it, I may not do it. I mean, nobody knows what I'm going to do.' Trump emphasised that Iran faces 'a lot of trouble' and expressed frustration that Tehran had not sought negotiations sooner, saying, 'Why didn't you negotiate with me before – all this death and destruction?'
Despite the uncertainty, US military movements suggest preparations for possible long-range air raids.
Over 31 US Air Force refuelling aircraft, including KC-135 Stratotankers and KC-46 Pegasuses, were tracked flying east towards Europe and beyond, indicating logistical support for extended bomber missions.
The B-2 Spirit stealth bomber, capable of carrying two GBU-57 bombs and boasting a range of approximately 6,000 miles without refuelling, is the only aircraft certified to deliver the MOP.
Known for its stealth capabilities and ability to penetrate sophisticated air defences, the B-2 typically operates from bases such as Whiteman Air Force Base in Missouri, Fairford in Gloucestershire, or Diego Garcia in the Indian Ocean—the latter being strategically closer to Iran.
In October 2024, B-2 bombers conducted strikes on underground Houthi weapon facilities from Whiteman AFB, demonstrating their long-range precision strike capability. Diego Garcia's proximity to Fordow, about 3,200 miles away, would allow B-2s to reach the target with refuelling support on the return leg.
The Fordow Fuel Enrichment Plant is one of Iran's two main uranium enrichment sites, carved deep into a mountain near Qom. It is estimated to lie 80 to 90 metres underground, shielded by hundreds of feet of rock and reinforced concrete, making it highly resistant to conventional airstrikes.
Israeli weapons, including the GBU-28 and BLU-109 bunker-buster bombs, lack the penetration capability to reach Fordow's depths, leaving the US GBU-57 as the only conventional munition capable of potentially destroying the facility.
The GBU-57 MOP weighs 30,000 pounds, with approximately 6,000 pounds of high explosives encased in a hardened steel shell designed to blast through layers of rock and concrete. Equipped with a GPS-guided precision targeting system and a delayed-action fuse, it can penetrate up to 200 feet underground before detonating.
Despite its formidable design, experts caution that the bomb may not fully destroy Fordow due to the facility's unknown exact depth and possible additional underground structures.
Fordow is a fortified uranium enrichment facility situated near the city of Qom in central Iran. Built inside a mountain, it covers roughly 54,000 square feet and houses approximately 3,000 centrifuges used for uranium enrichment.
Its underground location, estimated to be 80 to 90 metres (about 300 feet) below the surface, provides it with natural protection against conventional airstrikes.
The International Atomic Energy Agency (IAEA) has confirmed that Fordow remains operational and undamaged by recent Israeli attacks, making it a critical component of Iran's nuclear programme and a key target for any potential military intervention aimed at curbing Tehran's nuclear ambitions.