June 18, 2024 | Flash Brief

U.S., Israel Investigate Iranian Nuclear Modeling

June 18, 2024 | Flash Brief

U.S., Israel Investigate Iranian Nuclear Modeling

Latest Developments

The U.S. and Israeli governments are investigating new intelligence about Iranian computer modeling activities that could support the research and development of nuclear weapons, Axios reported on June 18. The intelligence spurred “suspicion,” “concern,” and questions about Iran’s quiet nuclear advancements, U.S. and Israeli security officials told Axios. If confirmed, ongoing Iranian efforts to build a nuclear warhead would contradict the U.S. intelligence community’s longstanding position that Iran halted its nuclear weaponization efforts in 2003.

Yet neither the United States nor Israel believes that Iranian Supreme Leader Ali Khamenei has officially resumed Iran’s military nuclear program, sources said. An anonymous U.S. security official clarified that there has been “no change to our assessment that Iran is not currently undertaking the key nuclear weapons development activities necessary to produce a testable nuclear device,” a position the U.S. intelligence community has held since 2019.

On June 18, senior U.S. and Israeli security officials are discussing this intelligence during a meeting of a high-level, U.S.-Israel strategic consultive group assembled to assess the progress of Iran’s nuclear program, among other issues. The discussion will be chaired by White House National Security Advisor Jake Sullivan, Israeli Minister for Strategy Affairs Ron Dermer, and Israeli National Security Advisor Tzachi Hanegbi.

Expert Analysis

“This apparent, coordinated leak by Washington and Jerusalem is likely designed to show Tehran that the program is penetrated and to forestall further nuclear weapons work. Yet how much of Iran’s ongoing weaponization activities are the two countries missing? The International Atomic Energy Agency needs an immediate mandate from member states to investigate and ensure an end to any Iranian weaponization efforts.” — Andrea Stricker, FDD Research Fellow and Deputy Director of FDD’s Nonproliferation and Biodefense Program

“There is no doubt that Tehran’s path to the bomb has been slow and steady, advancing what it can where and when it can. While the report leaves readers with more questions than answers about the state of Iranian weaponization, one thing is clear: Israel, America, and the international community will need to develop a baseline understanding of the moves Iran is implementing in order to make sense of these efforts and respond appropriately.” — Behnam Ben Taleblu, FDD Senior Fellow

Iran’s Past Work on Nuclear Weapons

Information collected by Western governments and the International Atomic Energy Agency (IAEA) and materials contained in Iran’s own archive of information, seized by Israel in 2018, indicate that Tehran had a structured nuclear weapons program up until 2003. The regime aimed to make five nuclear weapons initially and develop the ability to test them before moving to the production of a larger nuclear arsenal. However, under growing international scrutiny for illicit nuclear activities, Iran opted to halt the plan to produce nuclear weapons in mid-2003 but planned to hide and disperse weaponization activities, archive memoranda indicate. The U.S.-sanctioned Organization of Defensive Innovation and Research (SPND) likely remains in charge of any ongoing efforts.

In 2015, the IAEA released a report on Iran’s nuclear weapons activities that said, “By November 2011, the Agency had received information from Member States indicating that, prior to 2004 and between 2005 and 2009, Iran had undertaken computer modelling studies of various component arrangements, which were only specific to nuclear explosive configurations based on implosion technology.”

The IAEA added, “Open source information also indicated that Iran had conducted additional studies relating to high explosives modelling, which the Agency also considered significant in the context of both hydrodynamic simulation and code development studies. The modelling described above has a number of possible applications, some of which are exclusively for a nuclear explosive device.”

Experts from the Institute for Science and International Security assessed in 2021 that Tehran would likely draw on computer modeling as a key means to advance clandestine weaponization activities. Iran may have made substantial progress on weaponization, overcoming bottlenecks that existed as of 2003 — rendering it capable of exploding a crude nuclear device in under six months.

Washington Fails – Again – to Gauge Iran’s Nuclear Threat,” by Andrea Stricker and Behnam Ben Taleblu

What Will the U.S. Do to Stop a Nuclear Iran?” by Eyal Hulata

IAEA Members Vote to Censure Iran Over Nuclear Violations,” FDD Flash Brief

Iran Expands Uranium-Enrichment Capacity,” FDD Flash Brief


Iran Iran Global Threat Network Iran Nuclear Nonproliferation