Even though last June's joint U.S.-Israeli strikes devastated Iran's enrichment facilities at Natanz and Fordow, killing nuclear scientists and destroying key infrastructure, the war could not erase the technical knowledge Iran accumulated over the preceding seven years. By June 2025, Iran's most advanced centrifuges were roughly six times more efficient than those operating under the original 2015 nuclear accord, the Joint Comprehensive Plan of Action (JCPOA). More alarmingly, Iran had tripled its centrifuge installation speed, meaning that even if forced to rebuild its nuclear infrastructure from scratch, Tehran could produce weapons-grade fissile material in as little as six months — less time than the year-long breakout window the 2015 deal was designed to guarantee.
The Inspection Gap
Beyond enrichment speed, a second and arguably more dangerous problem looms: critical gaps in international inspectors' knowledge of Iran's nuclear activities. Iran has a documented history of covert enrichment; both the Natanz and Fordow facilities were built secretly, violating the country's obligations to the International Atomic Energy Agency (IAEA). Since 2021, when Tehran suspended advanced IAEA monitoring in retaliation for the assassination of nuclear scientist Mohsen Fakhrizadeh, Iran has produced tens of thousands of centrifuges — and even if only a few hundred were diverted to hidden facilities, they could be used to rapidly produce weapons-grade material.
The authors — Matthew Sharp of MIT's Center for Nuclear Security Policy and Nate Swanson of the Atlantic Council, both veterans of the U.S. Iran negotiating team — argue that any new agreement focusing solely on enrichment levels and uranium stockpiles will be dangerously insufficient. A credible deal must require Iran to fully re-implement the Additional Protocol, enabling IAEA inspectors to investigate undeclared nuclear sites, and must compel Tehran to account for every centrifuge produced since 2021. Crucially, the deal must also address weaponization activities — computer modeling, conventional explosives testing, and warhead design work that can be conducted in small, easily concealed facilities — areas that U.S. intelligence agencies in 2024 quietly concluded Iran may have resumed pursuing.
Trump's Blind Spot
Sharp and Swanson express pointed concern that the Trump administration has made "little public mention" of verification and IAEA monitoring as core components of any future accord. They warn that the same lack of advance planning that characterized the U.S. war effort risks infecting the nuclear diplomacy — and that a deal which fails to address covert enrichment capacity or weaponization would not prevent Iran from obtaining a nuclear weapon, but would merely "push Iran's effort further underground."