WHAT CHANGED SINCE MARCH

When this briefing was first published in mid-March 2026, the US–Israeli air campaign against Iran was two weeks old. Six months later the picture is fundamentally different from the one analysts worked with for most of the past decade. The old question — how many weeks Iran would need to enrich enough uranium for a bomb — no longer has a usable answer. The centrifuge halls that question was built around are wrecked. What remains is a smaller, harder problem: a stockpile of highly enriched uranium that nobody outside Iran can locate or measure, held by a leadership that has just fought a war over it.

This update covers the damage to the program, what is known about the missing material, the rise and collapse of the Islamabad Memorandum, the IAEA's September referral to the Security Council, and the scenarios that follow from here.

440.9kg
60% uranium, last verified June 2025
~22,000
Centrifuges destroyed or inoperable
20
Declared sites closed to the IAEA
0
Enrichment-site inspections since 28 Feb

TIMELINE: FROM STRIKES TO REFERRAL

KEY NUCLEAR SITES: DAMAGE ASSESSMENT

Fordow Enrichment Facility

Fordow, built inside a mountain near Qom, was the main producer of Iran's 60% material and the reason the US GBU-57 penetrator entered the public vocabulary. The Institute for Science and International Security (ISIS) assesses the plant as heavily damaged or destroyed by the June 2025 strikes. Its tunnel entrances remain sealed and commercial satellite imagery shows no sign of rebuilding. Damage estimates vary between sources, and no inspector has been underground since the attack, so the condition of the centrifuge halls is an assessment rather than a verified fact.

Natanz Enrichment Complex

Natanz has absorbed more ordnance than any other site. The above-ground pilot plant was completely destroyed in June 2025 and the underground Fuel Enrichment Plant was rendered inoperable. The 2026 campaign returned to it three times in March before destroying the surface access points on 27 March. Iran has carried out salvage work at the pilot plant under covers that block satellite view.

Isfahan and Arak

Isfahan is now the most important site in the file. The strikes destroyed the uranium conversion facility — and with it Iran's ability to make uranium hexafluoride, the gas that feeds centrifuges. But the tunnel complex beside it is where ISIS and an analysis published by the Bulletin of the Atomic Scientists believe most of the highly enriched uranium was moved before the June 2025 attack: an estimated 60–70% of the 60% stockpile, or roughly 265–287 kg. The tunnel entrances were hit in 2025 and later backfilled by Iran. A new enrichment plant Iran declared inside the same complex in June 2025 has never been inspected. The Arak heavy water plant was struck on 27 March 2026.

Pickaxe Mountain

A deeply buried complex under construction south of Natanz, known as Pickaxe Mountain, is the last major nuclear-linked site that has not been bombed. ISIS considers it a less likely hiding place for the stockpile than Isfahan, but President Trump has publicly threatened to strike it, describing it as central to any Iranian attempt to restore enrichment. Separately, imagery reported in September shows rapid rebuilding at a fortified facility inside the Parchin military complex that was previously linked to weapons-related research.

INTELLIGENCE NOTE

"For the first time in 20 years, Iran has no identifiable route to produce weapon-grade uranium" through centrifuge enrichment, the Institute for Science and International Security concluded in its June 2026 analysis — while declining to publish a breakout estimate at all, because doing so "would require unsubstantiated speculation" about centrifuges that may have survived. Both halves of that sentence matter: the known program is broken, and the unknown one cannot be measured.

THE MISSING STOCKPILE

Uranium enriched to 60% is not weapons-grade, but most of the enrichment work needed to reach 90% has already been done. Using the IAEA's own yardstick of about 42 kg of 60% material per weapon if further enriched, 440.9 kg is theoretically enough for around ten devices. That arithmetic is why the stockpile, rather than the ruined plants, dominates every negotiation.

The IAEA's position is blunt: it "cannot provide any information on the current size, composition or whereabouts" of Iran's enriched uranium. The agency observed vehicle activity around the Isfahan tunnels before it lost access, but it cannot say whether the cylinders are still there, were dispersed, or were buried by the strikes. Turning that material into a weapon would still require working centrifuges to finish enrichment, conversion to metal, and a weaponization effort — all of which have been targeted. The 2026 campaign hit between four and seven additional sites tied to weaponization research on top of five struck in 2025, along with centrifuge workshops at Karaj.

The honest assessment is therefore a range, not a number. At one end, the stockpile is entombed and Iran's route to a bomb is closed for years. At the other, a few hundred advanced centrifuges survived somewhere undeclared, and the material is closer to use than anyone can prove. Without inspectors there is no way to narrow that range.

IAEA MONITORING AND ACCESS

Verification in Iran has effectively ended. The agency stopped all in-field work on 28 February 2026. Since then its only activity has been a refuelling inspection at the Bushehr power reactor on 1–3 June; twenty other declared sites remain closed. Iran has not implemented the Additional Protocol, has not supplied design information for new facilities, and surveillance equipment at the enrichment sites is either destroyed or disabled.

Director General Rafael Grossi told the Board on 7 September that the situation was "a matter of serious proliferation concern" that must be addressed "with the utmost urgency". His report of 1 September (GOV/2026/50) states that Iran provided no access to nuclear facilities and prevented all field verification during the reporting period.

Two days later the Board acted. A resolution tabled by France, Germany, the United Kingdom and the United States, with thirteen co-sponsors, fulfilled the Board's statutory duty to report Iran's non-compliance — first formally found in June 2025 and deferred at three successive meetings — to the UN Security Council and General Assembly. The sponsors stressed that the step does not close the file or rule out a negotiated outcome. Tehran's reaction has been hostile. The head of Iran's atomic energy organization was barred from the IAEA's annual General Conference in Vienna, and Mohsen Rezaei of the Supreme National Security Council warned that "political and destructive actions" by the agency would "push countries toward leaving the Nuclear Non-Proliferation Treaty".

DIPLOMATIC TRACK: THE ISLAMABAD MEMORANDUM AND ITS COLLAPSE

The memorandum signed on 17 June — by President Trump at Versailles after the G7 summit, and by President Pezeshkian in Tehran — was brokered chiefly by Pakistan with support from Qatar, Saudi Arabia, Turkey and Egypt. On the nuclear file it said little: Iran reaffirmed that it would not seek nuclear weapons, and the two sides agreed to address the existing stockpile in a final deal, "with the minimum methodology to be down blending on site" under IAEA supervision. Enrichment limits, missiles and regional allies were all deferred to the 60-day negotiation. In exchange came a lifting of the US naval blockade, a 60-day licence for Iranian oil sales, toll-free passage through the Strait of Hormuz, and a reconstruction pledge of at least $300 billion with no stated source of funds.

It unravelled within three weeks, and not over uranium. The main failure points were:

After Iran fired on three commercial vessels near the strait on 7 July, Washington revoked the oil licence and declared the deal dead; Iran suspended its commitments on 18 July. Since the 17 August expiry, President Trump has said no talks are under way and promised a "crushing economic operation". Tehran says negotiations cannot resume until the US "makes amends" for its violations. Pakistan and Oman are still working separate channels, and Iran has continued talks with Oman on managing the strait. The practical consequence for the nuclear file is that the one mechanism that would have put inspectors next to the stockpile — supervised down-blending — never started.

THE NPT WITHDRAWAL DEBATE

Calls to leave the Non-Proliferation Treaty have circulated in Iran's parliament since the first strikes and intensified in late March as nuclear sites were hit during the war. The Security Council referral has revived them. The argument of the hardline camp is simple: membership did not protect Iran's safeguarded facilities from attack, so it offers nothing. The counter-argument, made by figures inside the establishment, is that withdrawal would be "a strategic trap" — surrendering Iran's remaining legal standing, unifying the Security Council against it, and handing Washington and Israel a justification for further strikes.

Withdrawal under Article X takes three months from notification. No notification has been made. But under a new supreme leader who has rarely appeared in public since March, and with President Trump's threats against Pickaxe Mountain feeding open calls in Tehran for a weapon, the internal balance is harder to read than at any point since the treaty debate began.

IRAN'S REGIONAL NETWORK

The "Axis of Resistance" that once gave Tehran strategic depth is much reduced. Hezbollah lost most of its senior leadership and arsenal in 2024, and the fall of the Assad government that December cut the land route through Syria. Fighting in Lebanon since early March 2026 has killed more than 3,000 people and displaced over a million, and Israeli forces hold roughly a fifth of Lebanese territory. Iran's remaining leverage has shifted from proxies to geography: its ability to threaten shipping in the Strait of Hormuz has proved a more effective pressure point in 2026 than any allied militia.

OUTLOOK

Three scenarios frame the months ahead:

The indicators to watch are IAEA access to any site beyond Bushehr, activity at the Isfahan tunnel entrances and Pickaxe Mountain, formal steps in Iran's parliament toward Article X, and whether the Security Council takes up the referral. The program's infrastructure has been set back by years. The risk has not fallen in proportion, because the part of the program that matters most is now the part no one can see.

FREQUENTLY ASKED QUESTIONS

Does Iran have nuclear weapons in 2026?

No. There is no evidence that Iran has built a nuclear weapon. Its known enrichment plants were destroyed or disabled by strikes in June 2025 and February–April 2026. However, about 440 kg of uranium enriched to 60% has not been verified by inspectors since June 2025.

Where is Iran's enriched uranium now?

Nobody outside Iran can say with certainty. Independent analysts believe most of it was moved into the tunnel complex at Isfahan before the June 2025 strikes. The IAEA states that it cannot provide any information on the stockpile's current size, composition or whereabouts.

How close is Iran to building a nuclear bomb?

The pre-war estimate of one to two weeks to produce weapons-grade uranium no longer applies, because the centrifuge plants it assumed are out of action. The Institute for Science and International Security says Iran currently has no identifiable centrifuge route to weapons-grade uranium, but declines to give a new timeline because surviving undeclared centrifuges cannot be ruled out.

What did the IAEA Board decide in September 2026?

On 9 September 2026 the Board of Governors adopted a resolution reporting Iran's non-compliance with its safeguards agreement to the UN Security Council and General Assembly — the first such referral in about twenty years.

What was the Islamabad Memorandum and why did it fail?

It was a 14-point US–Iran memorandum signed on 17 June 2026 to end the war and open 60 days of talks on a final deal. It collapsed in early July over disputed shipping routes in the Strait of Hormuz, continued Israeli operations in Lebanon, and ambiguous sanctions language. It expired on 17 August without a final agreement.

Will Iran leave the NPT?

Hardline politicians are pushing for withdrawal and senior officials have hinted at it, but no formal notification has been made. Withdrawal takes effect three months after notice under Article X of the treaty.

Are IAEA inspectors still in Iran?

Only marginally. Since 28 February 2026 the agency's sole inspection has been at the Bushehr power reactor in early June. It has no access to Fordow, Natanz, Isfahan or any other enrichment-related site.

AUTHOR

EDITOR · ENERGY & HYBRID CONFLICT

Arda Alkis is an energy and hybrid conflict analyst specializing in maritime security, strategic chokepoints, and irregular warfare. His work is based on open-source intelligence and data from ACLED (Armed Conflict Location & Event Data), the International Crisis Group (ICG), and international reporting networks. He focuses on energy-driven conflicts, proxy warfare, and instability across the Middle East, Africa, and global trade corridors.

Read more about the WarWatch editorial team on the About page.

SOURCES AND REFERENCES

MONITOR IRAN AND MIDDLE EAST IN REAL TIME

⊙ OPEN LIVE MAP

RELATED INTELLIGENCE BRIEFINGS

UKRAINE
Ukraine War Frontline Situation Report — September 2026 Update
RED SEA
Red Sea Crisis 2026: Houthi Blockade, Bab el-Mandeb Takeover and Global Shipping