The 22 June strike by the United States on Iran’s nuclear facilities at Natanz, Fordow and Isfahan risks replacing known quantities—monitored, visible sites—with a dangerous blind spot. Iran’s program may now shift into more inaccessible recesses.
By targeting what could be surveilled, the US may have unintentionally obscured Iran’s next moves, complicating future tracking and deepening strategic uncertainty.
Physical nuclear installations, regardless of their suspected activities, are invaluable sources of intelligence. The centrifuge facilities in Natanz, the tunnels in Fordow and the conversion plants in Isfahan were under comprehensive monitoring by the International Atomic Energy Agency (IAEA) and by US and Israeli intelligence agencies.
IAEA inspections, further restricted by Iran since 2021, nevertheless yielded information about uranium stockpiles, enrichment levels and centrifuge activity. Satellite imaging monitored operations at these locations. Human intelligence, gaining information from defectors and clandestine operations, augmented technical gathering, while signals intelligence captured communications associated with these permanent sites.
These installations were known entities. Their locations, configurations and operations limited Iran’s capacity to function covertly. Natanz’s above-ground infrastructure, despite enhancements following the Stuxnet computer virus attack discovered in 2010, were still susceptible to aerial monitoring. The subterranean configuration of Fordow constrained its scalability, hence restricting enrichment production.
This transparency, however limited, enabled measured responses ranging from sanctions to cyberattacks, without the need for kinetic operations.
The US air strikes with B-2 bombers and bunker-busting ordnance have now wrecked critical infrastructure. Reports suggest Natanz’s centrifuge assembly was heavily damaged, Fordow’s tunnels were compromised and Isfahan’s conversion facilities were hit. Iran’s claim that it evacuated nuclear materials implies potential continuity of operations, even as the physical sites may now be rubble or severely impaired.
This destruction could disrupt intelligence collection in several ways. The IAEA’s monitoring framework might be crippled, as there may not be much left at the sites for on-site inspections to inspect. Moreover, Iran’s has threatened to expel IAEA inspectors. Satellite imagery could lose utility, and Iran could relocate operations to covert sites, as it did after 2002 when Natanz was exposed.
New challenges may arise for human and signals intelligence if scientists and technicians who have been associated with known facilities now move to secret sites. Intercepting their communications or recruiting them as informers will be more difficult.
The decision to strike was a choice to eliminate visible threats at the potential cost of long-term visibility. It assumes that physical damage may impede Iran’s nuclear advancement more significantly than covert relocation may expedite it.
Experience suggests a more complex outcome may be in prospect. After the 2010 Stuxnet attack, the Shi’ite regime reconstructed Natanz, installing modern IR-9 centrifuges that enhanced enrichment efficiency. After the death of scientist Mohsen Fakhrizadeh in 2020, Iran enacted legislation to augment its program, achieving 60 percent uranium enrichment by 2021. Each disruption compelled Iran to adjust, and adjustments often resulted in less transparency.
The B-2 strikes, far more destructive than prior sabotage efforts, will hamper Iran’s progress, yet this may perpetuate the clandestine cycle on a grander scale.
Iran’s nuclear knowledge—its designs and the expertise of its scientists—persists despite sustained attacks on its personnel, as physical sites house only part of the program. Its nuclear programme could shift to smaller, dispersed facilities, as North Korea’s did with its Yongbyon reactor, or it could repurpose civilian sites, such as universities, as Pakistan did in its early program. These could be harder to detect and monitor.
Iran’s nuclear archive, published by Israel in 2018, revealed a decentralised network of research labs, suggesting covert infrastructure was in place. New sites in the future might lack Natanz’s size, but they might support unobserved low-level enrichment.
The possible intelligence gap might aggravate several threats. Unreliable data on Tehran’s capabilities may undercut deterrence by leaving the US and Israel unsure of how to respond, perhaps leading to escalation or miscalculation. It might complicate diplomacy, given the 2015 Joint Comprehensive Plan of Action, intended to restrain Iran’s progress, was based on IAEA surveillance of known sites. With those potentially gone and Iran threatening departure from the Treaty on Non-Proliferation of Nuclear Weapons, reopening negotiations may be more difficult.
An intelligence gap might raise proliferation concerns, because unmonitored materials or expertise could leak to non-state actors, particularly if Iran’s beleaguered security system fails to protect relocated assets.
The alternative to all this—refraining from strikes—carried risks. In early 2023 and again in 2024, IAEA inspectors found traces of uranium enriched to 83.7 percent at the Fordow Fuel Enrichment Plant. Ongoing surveillance might have prolonged the decision-making process excessively, permitting Iran to surpass the nuclear threshold. This is usually understood to require 90 percent enrichment, which requires very little more processing of material that has reached 83.7 percent.
However, the strikes may have merely exchanged a singular, known threat for a multitude of unknowns, wagering that Iran’s economic limitations and internal discord may hinder its capacity for covert reconstruction. The current challenge may reside in manoeuvring through this ambiguity, striking a balance between aggressive intelligence gathering and diplomatic caution to avert a nuclear Iran from emerging unseen.
The map, once partially lit, may now be entirely dark, and the stakes may be higher than ever.