Should the US enter the conflict between Israel and Iran, it would be expected to play a key role in destroying Iran\u2019s underground uranium enrichment facilities.<\/p>\n
That task would almost certainly fall to a select number of US bomber planes that are big enough to deliver a 30,000lb precision-guided bomb, known as the GBU-57 E\/B Massive Ordnance Penetrator, or MOP \u2014 the world\u2019s most powerful non-nuclear bomb.<\/p>\n
Dropped from a B2 stealth bomber, the 6m-long MOP can reportedly penetrate with sheer kinetic force more than 60 metres of rock and soil \u2014 depending on the earth\u2019s hardness \u2014 before exploding. Because it is precision-guided, multiple bombs can in theory be dropped on a single spot.<\/p>\n
That gives the MOP, which is more powerful than any known conventional bomb in Israel\u2019s arsenal, potentially enough impact to destroy much of Iran<\/a>\u2019s underground enrichment facilities, especially the Natanz site, which is thought to be buried 20 metres underground and encased in some 2 metres of reinforced concrete.<\/p>\n However, it may not be enough to destroy the more-heavily protected Fordow facility, which is buried inside a mountain under as much as 80 metres of rock and soil \u2014 even though the bomb was developed for that specific purpose.<\/p>\n Rafael Grossi, head of the International Atomic Energy Agency, has said that some of Fordow\u2019s most sensitive facilities may be buried even deeper, as much as half a mile underground.<\/p>\n \u201cI have been there many times,\u201d he told the FT this month<\/a>. \u201cTo get there you take a spiral tunnel down, down, down.\u201d<\/p>\n The lack of any guarantee that a successful bomb strike, or even a series of strikes, would destroy most or all of any already enriched nuclear stockpile in Fordow recalls a similar predicament faced by the US in the past.<\/p>\n When the US was contemplating a pre-emptive bombing campaign against Soviet nuclear weapons stationed in Cuba during the 1962 Cuban missile crisis, a key concern was a potential failure to destroy all the targets \u2014 a risk calculus that prompted President Kennedy to opt for a naval blockade and diplomacy instead.<\/p>\n \u201cThe US Air Force were only confident that they could destroy 85 per cent of the targets \u2014 which is why there were also plans for a follow-up ground invasion,\u201d said Robert Pape, a US military historian and author of\u00a0Bombing to Win<\/em>, a landmark survey of 20th century bombing campaigns.<\/p>\n \u201cIn the Iranian case, how can the US National Security Council be sure that they are going to get everything? That is the big issue,\u201d he said.<\/p>\n Manufactured by Boeing, the MOP has been tested at the White Sands Missile Range in New Mexico but has never been used in active combat. That potentially introduces a second problem.<\/p>\n \u201cTo destroy Fordow, which the MOP was explicitly designed for, would probably take at least two bombs, each hitting exactly the same spot,\u201d Pape said.<\/p>\n \u201cThat may be fine, and I am sure the US Air Force has the technical capabilities. But it\u2019s never been done before in a real war.\u201d<\/p>\n The MOP\u2019s 22,000lb predecessor, the Massive Ordnance Air Blast or MOAB, colloquially known as the Mother of All Bombs, was less powerful but was used to devastating effect in Afghanistan in 2017. It was dropped on a cave complex operated by\u00a0an Islamic State affiliate in\u00a0Nangarhar Province.<\/p>\n The MOP \u2014 which was developed from 2002, first deployed in 2011, and periodically upgraded since then \u2014 is an improved and more targeted version of the MOAB: its explosive charge is bigger and is carried inside an extremely rigid metal casing that allows for penetration before explosion.<\/p>\n The US arsenal is thought to contain about 20 MOPs. Each bomb costs about $4mn, based on a 2011 $28mn UA Air Force contract for eight of them.<\/p>\n Only the B2 Spirit Stealth bomber is configured to carry and deliver the MOP. There are 20 B2 bombers in service, according to the US Air Force<\/a>, each of them capable of carrying two MOPs, one in each of its bomb bays.<\/p>\n The bomber, made by Northrop Grumman, has an unfuelled range of 11,000km, or 19,000km with one mid-air refuelling \u2014 making almost any target in the world reachable.<\/p>\n Despite the fearsome capabilities of both the MOP and B2 bomber, any mission to destroy the Fordow plant would face other tactical difficulties, Pape said.<\/p>\n![\"Graphic](\"https:\/\/www.ft.com\/__origami\/service\/image\/v2\/images\/raw\/https%3A%2F%2Fd6c748xw2pzm8.cloudfront.net%2Fprod%2Fcb87d910-4c39-11f0-a0bc-df01cc684717-standard.png?source=next-article&fit=scale-down&quality=highest&width=700&dpr=1\")
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