“We definitely can’t say it was obliterated.” That candid analysis by a U.S. official, quoted in the wake of Operation Midnight Hammer, sums up the uneasy hesitancy now afflicting defense experts and policymakers. Even after deploying America’s strongest conventional weapon the 30,000-pound Massive Ordnance Penetrator (MOP) and the accuracy of B-2 stealth bombers, no more than one of Iran’s three main nuclear facilities, Fordow, seems to have endured devastating damage. The destiny of the other facilities, Natanz and Isfahan, is also unclear, with initial intelligence indicating their destruction was by no means complete.
At Fordow, American planners conducted a precision-modelled attack, dropping twelve MOPs via ventilation shafts into the mountain-hidden facility. The MOP, or GBU-57, is a marvel of technology: a GPS-guided, high-strength steel penetrator, intended to deposit its explosive payload hundreds of feet below ground with structural integrity intact. Each fuze for a bomb was customized-programmed to achieve maximum effect, with the delay being customized to penetrate maximally before explosion. As General Dan Caine puts it, “The fuze is effectively what tells the bomb when to function. A longer delay in a fuze, the deeper the weapon will penetrate and drive into the target.”
Still, even this engineering may has its limitations. Fordow’s primary centrifuge halls are located under an estimated 80–100 meters of soil and rock, with several sealed doors and defensive installations seen in pre-attack satellite imagery. Though surface craters and smoke plumes indicate significant disruption, analysts can’t be sure that the deepest centrifuges were taken out or if Iran was able to move them prior to the attack. The congressional aide debriefing on the operation said, If they were not present, then they are back in business. That is the key component to enriching the material.
Natanz, Iran’s biggest enrichment complex, had previously suffered Israeli bombing of aboveground substations and support facilities. U.S. B-2s then struck with two MOPs, which reportedly damaged some of the belowground rooms. But the Defense Intelligence Agency’s initial assessment concluded that “the bombs did not fully eliminate the sites’ centrifuges and highly enriched uranium.” Instead, most of the damage was confined to aboveground facilities, which has raised questions about the robustness of Iran’s belowground engineering.
Isfahan, rated by the Pentagon as “pretty much impenetrable,” was not hit with bunker-busters at all. A U.S. submarine instead fired a salvo of Tomahawk cruise missiles at surface installations. The decision took into account the facility’s even deeper and more difficult geology than Fordow, in addition to solid air defenses that made it harder to assess the risks in manned bomber missions.
The technical difficulties of demolishing these facilities are inherent in their construction. Iranian nuclear engineers have dedicated decades to making sites resistant to exactly such attacks, placing them deep underground under mountains, encasing them in concrete and steel, and reducing access points to vulnerabilities. According to New Civil Engineer, Fordow’s construction includes several underground halls, dense rock overburden, and a maze of support buildings and security fences. These defenses are not merely architectural they are strategic, drawn from lessons of previous sabotage, like the Stuxnet cyberattack that crippled Natanz’s centrifuges in 2009.
The consequences of the attacks have renewed discussion about the effectiveness of traditional bunker-busters. Although the MOP is the current height of U.S. penetrator technology, its performance is still being measured against actual results. An official from the defense department clarified, “We will take this information and determine did things work the way that we wanted them to… Or did things not work exactly as planned, and how can we fix that so that in the future our next-generation capabilities work that much better?”
Future versions might incorporate ‘smart fuze’ technology to more accurately account for target uncertainty and maximize destructive effects. The implications go beyond engineering. Iran’s nuclear infrastructure surviving partly or otherwise has an instant impact on proliferation and regional security. As former Mossad official Sima Shine succinctly phrased it: They want the bomb… nuclear deterrence. But the Iranians know the price they might pay for resumed nuclear activity. The destiny of Iran’s 400 kilograms of 60% enriched uranium is uncertain, something which U.S. and Israeli authorities admit could provide for speedy reconstitution of weapons capability if not checked.
Operation Midnight Hammer has therefore become a study in the convergence of military technology, underground engineering, and geopolitics. The technical race between facility hardening and bunker-buster development goes on, with each advancing on the fly. Until then, the world holds its breath as intelligence agencies sift over satellite imagery and sensor readings, looking for telltale signs of what happens beneath the wreckage and possibly what is yet to come.
