TEHRAN, July 19 — Six years after the United States withdrew from the Joint Comprehensive Plan of Action, the nuclear deal that once capped Iran’s uranium programme, the Islamic Republic now holds enough enriched material for several nuclear weapons. The International Atomic Energy Agency reported in 2024 that Iran’s stockpile, the enrichment level, and its technical know‑how had all crossed the thresholds the 2015 agreement was designed to prevent.
The JCPOA, negotiated in 2015 between Iran and the P5+1 powers, limited Tehran’s uranium enrichment to 3.67 percent purity and its stockpile of enriched material to 300 kilograms. In return, sweeping economic sanctions were lifted.
The deal also gave the IAEA intrusive inspection rights to monitor compliance. For nearly three years that arrangement held. Then in May 2018, the Trump administration withdrew from the accord and reinstated sanctions.
Iran responded not by leaving the deal itself but by gradually abandoning each of its nuclear commitments, a step‑by‑step strategy that accelerated after the U.S. exit was complete. By January 2021, Iranian scientists were enriching uranium to 20 percent, a level that crosses into medical‑isotope territory but also brings a country within months of bomb‑grade material.
Three months later, in April 2021, enrichment reached 60 percent — a short technical hop from weapons grade. By 2023, the IAEA confirmed Iran was enriching to near 90 percent, the threshold for a nuclear device. Over the same period, Iran’s total enriched stockpile far exceeded the 300‑kilogram JCPOA cap.
Agency inspectors reported in 2024 that the country has enough fissile material, if further enriched, for multiple bombs. Iran has yet to assemble a nuclear device, but the IAEA has documented simulated computer models of nuclear‑warhead development — work that falls under what the agency calls the Possible Military Dimensions, or PMD file.
Key facilities and a cyber strike
Three sites anchor Iran’s nuclear infrastructure. Natanz, a fuel enrichment plant that was sabotaged in 2021 by an explosion that damaged its centrifuge‑assembly facility, remains operational. Fordow, buried deep inside a mountain near the city of Qom, was built in secret and later disclosed; it now enriches uranium as well.
Isfahan houses a conversion plant where uranium ore concentrate is turned into gas for the centrifuges. These facilities are under continuous IAEA monitoring, but the agency’s access has been periodically restricted.
In 2025, the IAEA Board of Governors passed a series of censure resolutions against Iran for failing to provide adequate explanations about undeclared nuclear material and for restricting inspector access to sites like Fordow. The breakout timeline — the time needed to produce enough weapons‑grade uranium for a single bomb — is now measured in weeks, not months. That calculation depends on assumptions about centrifuge efficiency, the number of machines running, and the starting enrichment level.
At 60 percent, the remaining work is trivial. At near 90 percent, the line between having the capability and having the device is a matter of political intent, not technical capacity.
What the IAEA knows
The agency’s 2024 reports detail that Iran has conducted computer simulations of nuclear‑explosive devices — work that the PMD file, compiled over years, links to earlier military coordination. Iran insists its nuclear programme is peaceful; IAEA director‑general Rafael Grossi has said repeatedly that the agency cannot confirm that all nuclear material in Iran is for peaceful purposes. Neither Iran nor any other country has accused it of building a nuclear weapon.
But the simulated modelling, the enrichment trajectory, and the concealment of activities at several sites have kept the military‑dimension question alive through years of stalled negotiations. The 2015 deal was supposed to close that file.
Instead, the file has grown. For the Biden and subsequent administrations, the question has shifted from “can Iran be kept from the bomb?” to “how close is it, and what will stop it?” The 2025 censure resolutions at the IAEA were a diplomatic rebuke, but they carried no enforcement mechanism beyond naming and shaming. The U.S. government under President Donald Trump has maintained maximum‑pressure sanctions while leaving the door open to new talks.
No such talks have resumed. In the region, the stakes are concrete.
Saudi Arabia, the United Arab Emirates, and Turkey have all signalled that they would pursue their own enrichment capabilities if Iran crosses the weapons threshold. A cascade of nuclear programmes in the Middle East — the nonproliferation risk the JCPOA was created to prevent — is no longer a hypothetical. It is the logical endpoint of the path Iran is walking.
What comes next depends, in large part, on the decisions made in Tehran and Washington in the months ahead. The IAEA continues its inspections, but the material, the knowledge, and the infrastructure are already in place. The only missing piece is the political will to build a warhead — or the political will to stop it.
