Three weeks of intensive US and Israeli strikes on Iran’s ballistic missile infrastructure have destroyed radar systems, collapsed tunnel entrances, and cratered ventilation shafts across dozens of sites. Iran keeps firing. The reason, according to satellite analysis by CNN and assessments by Israeli security research centre Alma Research, lies not above the ground but hundreds of metres beneath it; inside a network of underground missile cities connected by internal railways, carved into mountains that no bomb in the current American or Israeli arsenal can fully reach.
Iran’s underground missile programme is not a recent improvisation. Reports that emerged as far back as 2020 claimed an automated railway system running through cavernous tunnels, transporting ballistic missiles between assembly halls, storage vaults, and blast-door exits. What is becoming clearer now, as Operation Epic Fury enters its fourth week, is the scale of what was built and the limits of what air power alone can do against it.
What the satellite imagery shows
CNN‘s investigation, published recently, analysed satellite images from 27 Iranian underground bases covering 107 tunnels. It found that the US-Israeli campaign had struck 77 per cent of the tunnel entrances it could image. It also found something more troubling: construction equipment appearing at bombed sites within 48 hours, digging out blocked entrances and restoring access to the tunnel systems below.
Alma Research, which has tracked Iran’s missile infrastructure for years, reached a similar conclusion in its January 2026 assessment, based on damage sustained during the June 2025 war.
It found that strikes on surface infrastructure had only temporarily rendered large missile launch bases inoperable. Any Iranian asset located within underground infrastructure, the centre concluded, survived.
One of the most discussed sites is near Yazd, in central Iran. The site has been struck by the United States and Israel on multiple occasions, including on March 1, March 6, March 17, and again in the days that followed.
Independent analyst Shanaka Anslem Perera, in a post on X, argued that the visible damage tells only part of the story: that the tunnel system below, with blast doors serving as separate exit points and a rail network that reroutes when one portal is lost, remains operational.
The physics of why bombs cannot finish the job
The central constraint is geological, and it has now been publicly stated by Iran itself. Former IRGC Aerospace Force commander Brigadier General Amir Ali Hajizadeh said that Iran built its missile bases across provinces and cities at a depth of 500 metres.
The most powerful weapon the United States has for destroying hardened underground targets is the GBU-57 Massive Ordnance Penetrator – a 30,000-pound bomb built specifically for this purpose. It can penetrate “approximately 60 metres of reinforced concrete or roughly 40 metres of moderate rock. Granite is harder than moderate rock. Five hundred metres is more than twelve times the weapon’s maximum penetration depth. The gap between the bomb and the tunnel is not a margin of error.”
It is, as Perera puts it, a physical impossibility, and the Iranian commander’s own statement suggests Tehran built its deepest facilities with precisely that gap in mind.
“The mountain does not care how many sorties are flown above it. The railway does not care how many portals are sealed. The geology is the defence, and the geology has been there for 300 million years,” observed Perera.
What this means for the war
The engineering logic, as Perera describes it, is straightforward: “Every missile that hits Arad, Dimona, or central Israel was assembled underground, moved on rails to an exit, and fired from a door that may have been destroyed and rebuilt multiple times since February 28. The persistence of Iranian missile fire despite three weeks of intensive strikes is not resilience. It is infrastructure. ”
“IRGC did not prepare for this war by building rockets. It prepared by building railways inside mountains. The rockets are replaceable. The railways are permanent. And the granite that protects them was formed before mammals existed. The strait is 21 miles wide. The mountain is 500 metres deep. And the railway inside it is still delivering missiles to the surface,” he added.
BREAKING: Iran built a subway system for ballistic missiles inside a granite mountain south of Yazd. Automated rails move warheads and transporter-erector-launchers between assembly halls, storage vaults, and three to ten blast-door exits carved into the mountainside at depths… https://t.co/vuTtgrSCeV pic.twitter.com/pTRz8vuwJ0
— Shanaka Anslem Perera ⚡ (@shanaka86) March 22, 2026
Iran has continued to fire ballistic missiles throughout Operation Epic Fury, including the attempted strike on the joint US-UK base at Diego Garcia. Trump has said the operation is running weeks ahead of schedule and that Iran’s military is finished. The satellite imagery and the institutional assessments tell a more complicated story: one in which the visible war, fought above ground, has made genuine progress, and the invisible war, fought half a kilometre underground, has barely begun.