Why Israel wants US bunker busters to hit Iran’s Fordow nuclear site | Israel-Iran conflict News

US President Donald Trump says he is still weighing his options regarding United States military intervention amid escalating hostilities between Israel and Iran.

Standing on the South Lawn of the White House on Wednesday, Trump said, “The next week is going to be big,” adding that Iranian officials are eager to negotiate. However, he warned them that “it’s very late to be talking,” after they reached out to him.

Officials and experts have suggested that the US’s 30,000-pound (13,000kg) bunker buster bomb is the only weapon capable of destroying the Fordow Fuel Enrichment Plant, a facility believed to be central to Tehran’s nuclear programme and carved deep into a mountain.

The United States is the only country to possess these bombs, which it delivers using B-2 bombers. If deployed against Iran, it would represent a major shift from primarily intercepting missiles on Israel’s behalf to conducting active offensive strikes against Iran.

What are bunker buster bombs?

“Bunker buster” is a general term for bombs designed to destroy targets located deep underground that conventional bombs cannot reach.

The US military’s most powerful bunker buster is the GBU-57 Massive Ordnance Penetrator. Weighing about 30,000 pounds (13,600 kg), including a 2,700kg (6,000-pound) warhead, this precision-guided bomb is made of high-strength steel and built to penetrate up to 200 feet (61 metres) underground before exploding.

The B-2 Spirit, a US stealth bomber, is currently the only aircraft designed to deploy the GBU-57 and can carry two bunker buster bombs at a time. The US Air Force says multiple bombs can be dropped sequentially, either by the same aircraft or by several, allowing each strike to burrow deeper, amplifying the overall impact.

Israel also operates US-made bunker busters, including the GBU-28 and BLU-109, which are typically dropped from fighter jets such as the F-15. These weapons, however, have a much shallower penetration range and are not capable of reaching extreme depths of fortified sites like Iran’s Fordow nuclear facility. In 2024, Israel reportedly used successive BLU-109 bombs to kill Hezbollah leader Hassan Nasrallah in his underground headquarters in Beirut.

How deep is Iran’s Fordow nuclear facility?

Iran’s Fordow Fuel Enrichment Plant, located about 95km (60 miles) southwest of Tehran, is built into the side of a mountain, reportedly up to 80-90 metres (260-300 feet) underground, to survive air strikes and bunker buster attacks.

Construction of the Fordow facility is believed to have begun in about 2006, and it became operational in 2009, the same year Iran officially acknowledged it.

Under the 2015 Iran nuclear deal, known as the JCPOA, Iran agreed to halt enrichment at Fordow and convert the site into a research centre. However, after the US withdrew from the agreement in 2018, Iran resumed uranium enrichment at the facility. Iran has insisted its nuclear programme is for civilian purposes.

Fordow is reportedly defended by Iranian and Russian surface-to-air missile systems, though those defences may have already been targeted in Israel’s ongoing strikes.

Israeli Prime Minister Benjamin Netanyahu has framed the campaign as a mission to dismantle Iran’s missile and nuclear capabilities, describing them as an existential threat. Officials have confirmed that Fordow is a key target.

“This entire operation … really has to be completed with the elimination of Fordow,” said Yechiel Leiter, Israel’s ambassador to the United States, in an interview with Fox News.

Other nuclear sites targeted

Israel is believed to have destroyed the above-ground section of Iran’s uranium enrichment facility at Natanz, the country’s largest nuclear site.

According to the United Nations’ International Atomic Energy Agency (IAEA), the resulting power loss may have also caused damage to the underground enrichment halls at the facility.

Before and after satellite imagery reveals the extent of the damage at Natanz.

Israeli attacks have also damaged the Isfahan enrichment facility in central Iran.

Potential nuclear and chemical contamination

On Monday, Rafael Grossi, the head of the UN nuclear watchdog, said there was a possibility of both radiological and chemical contamination from the damaged Natanz site.

Speaking at an emergency IAEA session in Vienna, Grossi said radiation levels remain normal outside Iran’s Natanz and Isfahan nuclear sites, both of which were hit in Israeli strikes. However, he warned that ongoing military escalation increases the risk of a radiological release.

Fordow is located about 32 kilometres (20 miles) south of the city of Qom, Iran’s seventh-largest city with a population of some 1.4 million and a major religious and political centre.