US Weighs Deploying 'Mother of All Bombs' Against Iran

According to US officials cited by CNN, Washington has drawn up plans to strike Iran's energy infrastructure and nuclear facilities with the largest non-nuclear bomb in its arsenal if President Donald Trump orders a resumption of military operations.

The weapon in question is the GBU-43/B Massive Ordnance Air Blast Bomb (MOAB), commonly known as the "mother of all bombs." Experts say deploying it could significantly escalate the conflict, just as fighting has paused.

Notably, skepticism about the plan's real effectiveness has surfaced even inside the Trump administration. Officials familiar with the military discussions told CNN and Al Jazeera that deploying the MOAB is unlikely to help the US achieve its stated strategic goals, including destroying Iran's nuclear capability.

Brussels-based military expert Elijah Magnier told Al Jazeera that using the MOAB does not even guarantee the destruction of Iran's deeply buried nuclear facilities, and that such a strike would most likely be "political theater."

What is the MOAB?

The GBU-43/B Massive Ordnance Air Blast Bomb is a large bomb containing about 8,500 kg (18,000 pounds, or 8.5 tonnes) of high explosive. The entire bomb weighs 9,800 kg (21,605 pounds, nearly 10 tonnes) — equivalent to the weight of four sedans — and is more than 9 metres (about 30 feet) long, roughly the length of a small yacht.

The MOAB is typically dropped from a Lockheed C-130 Hercules transport aircraft because it is too large to fit on a stealth bomber. The bomb was first produced in 2002-2003 and has undergone 12 detonation tests.

Its name was inspired by a remark by former Iraqi President Saddam Hussein during the 1991 Gulf War, when he spoke of the "mother of all battles."

The US has deployed the MOAB only once, in a 2017 strike on a cave and tunnel complex belonging to the Islamic State's Khorasan branch (ISKP) in Afghanistan. Afghan officials at the time said 94 ISKP fighters were killed and no civilians were hurt, though there were unconfirmed reports of civilian casualties and destroyed homes.

How destructive is it?

Designed to detonate a few feet above the ground, the MOAB produces lethal fire blasts on detonation and is built to blow away structures, cave entrances and other hardened surface features.

"Its purpose is to create an extremely powerful shock wave over a surface area," Magnier said.

Military expert Colonel Nidal Abu Zeid told Al Jazeera that the bomb does not need to make impact to detonate, and that its enormous blast would destroy anything on the ground within a 1 km (0.6 mile) radius.

According to Abu Zeid, the US would most likely aim to use the high-explosive MOAB to completely destroy Iran's above-ground ground-force positions while seeking ways to reach underground facilities, including Pickaxe Mountain — a target Trump has threatened to strike.

Magnier, however, argued that the bomb's radius and level of destruction depend heavily on the terrain where it is deployed and the population density of the area. He added that it may not be particularly effective against targets buried deep underground.

Some Iranian nuclear facilities the US might want to target, such as the Fordow complex and a site under construction at Pickaxe Mountain, are heavily fortified and located deep underground.

"Its large explosive payload can create a devastating shock effect on people, equipment and vulnerable exposed structures," Magnier said, but stressed: "The Afghanistan operation showed its intended use against a cave and tunnel site; it did not prove the ability to destroy every kind of underground structure."

Although its blast can reach below the surface, the MOAB is not specifically designed to penetrate thick concrete or mountain rock the way a "bunker-buster" bomb is. The US military's most powerful bunker-buster is the GBU-57 Massive Ordnance Penetrator, which weighs about 30,000 pounds (13,600 kg), including a 2,700 kg (6,000 pound) warhead. It is a precision-guided bomb made of high-strength steel, built to penetrate as deep as 200 feet (61 metres) underground before detonating.

Will the US actually use the MOAB?

Beyond not guaranteeing effective hits on underground targets, Magnier told Al Jazeera that deploying the aircraft needed in areas where nuclear facilities are located could also be difficult. The stealth bombers better suited to such terrain cannot carry a bomb of that size.

According to him, using the bomb could also destroy infrastructure without forcing Iran to make any concessions. He noted that deploying it risks turning "a spectacular event" into one that ultimately yields little political gain for Washington.

"The question I put to any commander who supports using it is simple: What will this weapon do that another available weapon cannot, and how will that outcome advance a viable political solution?" Magnier said.

"If the answer revolves around the spectacle of the explosion, then the proposal is stronger on political theater than on military strategy," he added.

CNN reported that in closed-door discussions, Trump is looking for a "decisive" way to end the war to prove Washington was never defeated.

How might Iran respond?

Experts say a MOAB strike would likely trigger a major response from Iran, warning that Tehran could even attack neighbouring countries that host US military assets.

For months, Iranian security officials have commented on the possibility of attacking countries such as Kuwait to capture American soldiers and force Washington to surrender.

In May, during a lull in the fighting, Kuwait accused sailors from Iran's Islamic Revolutionary Guard Corps (IRGC) of infiltrating Bubiyan Island, leading to a gun battle between the two countries' forces. One Kuwaiti was wounded and four Iranian soldiers were captured. Iran denied the infiltration, saying its soldiers' navigation system had malfunctioned.

On Tuesday, IRGC security adviser Mohammad Reza Naghdi warned that Iran could capture soldiers if Washington launched a ground attack, though military experts have long dismissed Trump's earlier threats of invasion because of Iran's mountainous terrain.

"If the US launches a ground attack, so many of their soldiers will be captured that they will be forced to raise the white flag," he said.

Experts say Iran is preparing for a new round of war by stockpiling weapons, reinforcing nuclear and key defence sites, and rallying allied forces.

In a broadcast on Sunday, Mohsen Rezaei, chairman of Iran's National Security Council, threatened that Tehran would strike the region's digital infrastructure, including telecom cables, data centres and artificial intelligence facilities in the United Arab Emirates and elsewhere, if US strikes continue.