New report exposes intact Iranian bunker that may hide regime’s ongoing nuclear work
A US think tank, the Institute for Science and International Security (ISIS), says it has identified an intact, partially underground bunker at Iran's Natanz nuclear complex that appears to have escaped American and Israeli airstrikes in 2025 and 2026. The finding matters because it suggests Iran may retain infrastructure capable of supporting large-scale uranium enrichment despite two rounds of military action aimed at crippling its nuclear programme, and raises questions about why the site was not targeted and whether Tehran could use it to resume weapons-related work undetected.
ISIS says the bunkered structure was built between 2010 and 2017, mainly from 2015 onwards, and was likely intended to store uranium hexafluoride to support enrichment at the Natanz Fuel Enrichment Plant, though no vehicle activity has been seen there since the June 2025 war. Iran nearly doubled its stockpile of 60%-enriched uranium to 440kg between December 2024 and June 2025, according to an earlier ISIS report, fuelling fears it was nearing weapons-grade capability. Iran is refusing to allow International Atomic Energy Agency inspections of bombed sites, a stance experts say breaches its non-proliferation obligations, while the IAEA notes it previously inspected the building regularly before mid-2025. Analysts including Jason Brodsky of United Against Nuclear Iran argue the site should be destroyed in any future strikes and that its existence highlights flaws in the earlier 2015 nuclear deal.
- Think tank finds intact bunker at Iran's Natanz nuclear site
- Site escaped 2025-2026 US-Israeli strikes, may aid enrichment
- Iran blocks IAEA inspections; experts urge destroying the facility
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The case for
Those who see this as evidence for further military and diplomatic pressure argue that Iran's near-doubling of its 60%-enriched uranium stockpile, combined with its refusal to allow IAEA inspections of bombed sites, shows Tehran retains both the material and the hidden infrastructure needed to resume weapons-relevant enrichment. They contend that an intact bunker built specifically to support the Natanz plant demonstrates the limits of the 2015 nuclear deal's verification regime and that leaving such facilities standing only invites clandestine reconstruction. On this view, destroying remaining enrichment-related infrastructure in any future strikes, while insisting Iran restore full IAEA access, is the surest way to prevent a covert path to a bomb.
The case against
Others argue that two rounds of strikes have not ended Iran's nuclear programme but have instead given Tehran stronger reasons to conceal facilities, expel monitors and abandon cooperation altogether, leaving the international community with less visibility than before the bombing began. They note that a bunker with no observed vehicle activity since June 2025 is not proof of an ongoing weapons effort, and that publicising and threatening to destroy every suspected site risks provoking further concealment or escalation rather than compliance. On this view, restoring IAEA inspections and pursuing renewed diplomatic engagement offer a more durable check on Iran's programme than additional military action, which has already shown its limits.