Proponents of the deal dismissed Israel’s findings. Steven Simon, senior director for the Middle East and North Africa on the National Security Council under President Barack Obama, called the archive a “nuclear nothingburger,” full of old documents on a weapons program Iran had shut down. Iran’s leaders declared the find a fraud. 

European leaders and the IAEA itself, working to save the nuclear deal, downplayed or ignored outright the documents, desperate to preserve a status quo with Iran that the United States and Israel seemed bent on wrecking. 

According to IAEA reports published since last year, the inspection agency hasn’t processed data from the Iran Nuclear Archive and has never asked Iranian officials for permission to inspect the rest of it. To date the agency has not used Israel’s findings—which are startling—to probe the extent of Iran’s nuclear capabilities.

For former IAEA inspectors who can speak without political consequences, finding the archive was like discovering missing puzzle pieces, or landing on a paved road with a map in what had been a fogged-in landscape lacking compass points. Key experts who have visited Iran’s declared nuclear sites and worked with its government records say the archive is authentic, not an Israeli hoax. They also say it shows that Iran—contrary to those insisting Iran’s nuclear pursuits are for peaceful energy purposes—has been much further along in developing nuclear weapons than was previously known. 

The Iranian cache contains names of people who worked on a nuclear weapons program, where they worked, and what equipment they used. It includes designs for warheads and notes on neutron research to create a nuclear explosion. Perhaps most telling, the archive includes “deception folders”—documents that actually enumerate the lies Iranian officials told IAEA officials as an effort to preserve consistency.

Robert Kelley, a nuclear engineer and former IAEA inspector, after reviewing the documents last year, said, “The papers show these guys were working on nuclear bombs.”

Olli Heinonen, a former IAEA deputy director general, delivered a more stark assessment last month in Jerusalem: “Iran is capable of producing fissile material for one nuclear device in six to eight months,” he said.

Based on his monthslong review of the archive, Heinonen told a gathering of experts and government officials, “We can speculate … it should not take more than a year for Iran to develop a fully functional nuclear missile.” Israel and the Gulf states, he said, “have a reason to worry.”

Heinonen was senior research officer at a reactor lab in Finland before joining the IAEA in Vienna, where he served 27 years. His Department of Safeguards, which he headed from 2005 to 2009, carries out all inspections tied to stopping the spread of nuclear weapons. Long before the JCPOA, it maintained a legally binding agreement with Iran to report nuclear activity. 

Heinonen has visited all the declared nuclear sites in Iran, some of them multiple times. He also was a key figure in the discovery of A.Q. Khan, the Pakistani nuclear physicist who for decades ran a black market in nuclear weapons technology, selling to Iran and North Korea the know-how that’s allowed them to become the threats they are today.

Before reaching conclusions about the Iran Nuclear Archive, Heinonen said he spent months doing “a deep dive” into the documents. “This was information I had not seen before,” he said. At IAEA, he said, the inspectors had “bits and pieces of information” about a military dimension to Iran’s nuclear program, “but not the kind of comprehensive view the archive gives you.”

For years, observers like Heinonen raised questions about Iran’s insistence on producing nuclear material, rather than buying it from other states as most do for civilian use. Why build an expensive nuclear infrastructure when you are an oil-producing state? Why invest at a time when global markets are awash in cheap natural gas? Why force Iranians to live under economic sanctions, when bringing a decisive end to the program could unleash the country’s wealth and international currency flows? The answer could only be it wanted to become one of the world’s handful of nuclear-armed powers.

Heinonen said the silence of the IAEA forced him and others to publish their conclusions. Starting earlier this year, he released 10 memos synthesizing those findings, published on the website of the Foundation for Defense of Democracies, where he currently serves as senior adviser. The memos are co-authored with other scientists and David Albright, president of the Institute for Science and International Security and a former IAEA adviser and UN weapons inspector in Iraq.

In summary, the archive shows that Iran planned to produce five nuclear weapons by the end of 2004, including one to be tested underground at a site under construction. To do that, it was testing fissile components at undisclosed sites, some under construction. 

Why build an expensive nuclear infrastructure when you are an oil-producing state? Why invest at a time when global markets are awash in cheap natural gas? Why force Iranians to live under economic sanctions, when bringing a decisive end to the program could unleash the country’s wealth and international currency flows?

The archive also showed Iran constructing a uranium mine and developing advanced centrifuges for military purposes, which it subsequently declared were for civilian use. These sites and others named in the archives were off-limits to IAEA inspectors, and remain so.

“The documents are not compatible with Iran’s statements on the peaceful nature of the program,” said Heinonen. “IAEA has been deceived. It has been deceived as late as 2015.”

Iran carried out the deception by operating a civilian program with a parallel program for nuclear weapons development, he said. Industrial infrastructure and research-and-development facilities served both, “and when you do it that way it’s very difficult to find that military program.”

Inspections have been hampered by the limits of the JCPOA, and a UN resolution, which emphasize uranium enrichment. “We have to understand a nuclear weapon is a system,” said Heinonen. The system is like a teepee stretched over three poles, he said: the delivery system, or missile; the weapon’s actual design; and the fissile material, made up of enriched uranium or plutonium. A focus only on one pole collapses an accurate view of the whole system. 

Heinonen concludes, “Iran in my view is in breach of its obligations.” 

The Iran Nuclear Archive shows Iran with ready designs along each of the three “poles,” while it in recent years has only divulged information on uranium enrichment. Further complicating the picture is that IAEA gave Iran a pass when it recently upgraded centrifuges, making weapons-grade enrichment more possible.

Though only a snapshot, stressed Heinonen, the archive creates a baseline understanding of Iran’s nuclear program that neither the IAEA nor any party to the JCPOA has been able to come up with.

In a March statement to the IAEA board of governors, Ambassador Jackie Wolcott, who is the U.S. representative to UN agencies in Vienna, said Iran had to answer for its nuclear archives: “The facts of Iran’s past nuclear weapons activities continue to have bearing on current questions about the possibility of undeclared nuclear material and activities in Iran. These issues must be addressed in a clear and straightforward manner, without further delay.”

Heinonen believes the decision by Trump to withdraw the United States from the nuclear agreement last year was a tactical error the Iranians will be “comfortable” with, though the agreement, he said, “definitely needs fixing.” They can withstand economic sanctions, he said, and now have the centrifuges needed to grow their production of high-enriched uranium.

Since the advent of nuclear weapons, he also points out, the United States has negotiated arms-control agreements with an array of belligerent adversaries without risking the use of force in response to violations. 

Iran’s leaders seem less fazed by sanctions, reimposed starting a year ago, than by recent actions by Secretary of State Mike Pompeo, who starting May 3 revoked waivers under the JCPOA allowing Iran to carry out aspects of its nuclear program, like shipping low-enriched uranium. The prospect of losing remaining waivers, which could wreck ongoing covert nuclear activity, may be what prompted President Hassan Rouhani’s mid-May withdrawal from the JCPOA. At the same time, Iran launched attacks on oil tankers in the Gulf of Oman and on June 20 shot down an unarmed U.S. drone. 

In a May 8 speech, Rouhani said Iran would quadruple uranium production in 60 days, and increase its level of enrichment. Quadrupling enrichment happened in June, and on July 1 Iran announced it had surpassed the limits set by the JCPOA and could begin enrichment to weapons grade. That’s significant: It marks the Islamic regime’s boldest departure from international norms. And the speed in ratcheting up enrichment shows a capacity more reflected in the archive. 

Ultimately, Heinonen believes, Iran will have to come to the negotiating table because too many other countries—including its Middle East neighbors and Russia—will oppose a nuclear-armed Iran. But the clock running toward such armament is ticking.