Haaretz reported on 18 May 2026, citing a regional source, that Iran's counter to the US five-point proposal offers domestic dilution of its enriched-uranium stockpile rather than transfer outside the country, and a 10-year enrichment moratorium against the US 20-year demand1. The US text, relayed by Tasnim and Fars and aggregated by Euronews, would require Iran to operate one nuclear site and surrender its enriched-uranium stockpile2. Iran's own 10-point counter-proposal, transmitted on 10 May, was rejected the same day.
The verification problem sits underneath both texts. François Diaz-Maurin, nuclear-affairs editor at the Bulletin of the Atomic Scientists, published satellite analysis on 18 May of a truck with 18 blue containers at the south tunnel entrance to Iran's Isfahan complex on 9 June 2025. The Bulletin estimated the load could carry up to 540 kg of 60%-enriched uranium, above the 440 kg figure the US MoU was built to recover3. A former Israeli intelligence official had already assessed that the June strikes left Iran's nuclear capacity intact; the Bulletin's satellite work corroborates the inventory side of that claim.
The gap means more than 100 kg of weapons-relevant material. The IAEA, locked out of Iran since the unanimous Majlis suspension vote on 11 April, has lost what its inspectors call continuity of knowledge. Neither the Bulletin's upper-bound estimate nor any Iranian dilution programme can be independently checked. A signed deal pegged to a 440 kg surrender therefore leaves up to 100 kg unaccounted for under an Isfahan mountain that no inspector can enter. The headline demand of the entire US framework may already be priced against a stale inventory, which is the kind of architectural problem that does not get fixed by adjusting timelines.
