Target: Iran. US forces are ready to deliver the second heaviest bunker buster ever made

Telegraph

5 hours ago

The US armed forces have made various significant moves in recent days and months, clearly in preparation for strikes on Iran.
First, in March, B-2 Stealth bombers were deployed to Diego Garcia in the middle of the Indian Ocean – a good base for operations against Iran. The B-2s cost more than a billion dollars each and the US only has 19 of them (21 were built but two have been wrecked in accidents): they are only used for the most important operations.
In this case, however, the B-2s were probably not deployed because of their stealth technology. The Israelis alone appear to have suppressed Iranian air defences to the degree that they can operate more or less at will in Iran's airspace, mostly not using stealthy aircraft. The US would clearly be able to do this too.
The significant thing about the B-2 for this mission is that it's the only aircraft operationally certified to carry the GBU-57 Massive Ordnance Penetrator, the MOP – America's most powerful deep penetration bunker buster. The MOP is so large and weighty (6m long and over 14 tonnes) that only heavy bombers like the B-2 can carry it. In the Western world, only the US has heavy bombers. This is the reason that only the US has such weapons. Israel could easily build a MOP, but it could not easily obtain an aircraft capable of dropping it.
The reason that a MOP is relatively easily built is that it is fairly unsophisticated. A MOP is mostly just a sharpened rod of solid hardened steel: only two-and-a-bit tonnes of its mass is explosive charge. Dropped from high in the stratosphere, it hits the ground going at many times the speed of sound and penetrates to great depths before exploding – exactly how deep is a secret but the figure of 60m is often mentioned. This might or might not be sufficient to reach the very deepest parts of the underground Iranian nuclear facilities at Fordow and Natanz, and the Iranians are believed to be tunnelling even deeper, so there is some pressure on Trump – especially from the Israelis – to use the MOP while it is still effective.
Some would see the MOP as a historical anomaly. It was developed in the noughties, but such weapons were last used for real in WWII. The British 5-tonne 'Tallboy' and 10-tonne 'Grand Slam' penetrators – designed by Barnes Wallis of Dambusters bouncing-bomb fame, and referred to as 'earthquake bombs' – were used against various hard targets such as U-boat pens. An even more monstrous weapon, the 20-tonne American T-12, arrived too late to see war service. The T-12 remains the largest ever weapon of this type, relegating today's MOP to second place. The MOP, however, benefits from modern smartbomb guidance technology, meaning that it is much more accurate than the various 1940s bunker busters.
Now we're seeing more moves indicating that US action may be imminent. The aircraft carrier USS Nimitz and her strike group are on their way into the Indian Ocean: the USS Carl Vinson and her group are already in the Red Sea. On Monday, a large formation of more than 20 air-to-air tanker planes was seen departing the US eastern seaboard on flight trackers: such a deployment would be likely if major air operations were expected.
And of course, President Trump has now left the G7 summit early after spending just a day in Canada, stating that Tehran should be evacuated and that he's seeking an outcome 'better than a ceasefire'.
'They should have done the deal. I told them, do the deal,' Trump told reporters. 'So I don't know. I'm not too much in the mood to negotiate.'
Since then he and others in his camp including Vice President J D Vance have appeared to prepare their supporters for the idea of American intervention. All the military pieces are now in place.
It's looking likelier and likelier that the MOP is about to see its first operational use.