What should be done about Iran’s potential secret chemical and biological weapons programs?

By Christina McAllister, Richard T. Cupitt | Opinion | April 2, 2026

Tehran during US-Israeli airstrikes last month. Credit: Avash Media via Wikimedia Commons. CC BY 4.0.Share

Ahead of a televised address Wednesday, critics wanted US President Donald Trump to lay out a clear roadmap for ending the now month-long war in Iran and clarify the objectives for having started it. Denying that his goal was ever regime change, Trump emphasized in his speech the objective of preventing Iran from possessing a nuclear weapon. However, the future course of the conflict remains nearly as murky on Thursday as it was the previous day, as does the future of Iran’s stockpile of highly enriched uranium. That’s also true of the status of possible secret chemical and biological weapons programs that appear to have received scant attention during recent events—despite years of US and likeminded-partner country concerns and sanctions.

After reportedly considering a ground-invasion to retrieve Iran’s highly enriched uranium, Trump said on Wednesday the country’s “nuclear dust” was inaccessibly buried under rubble and would be monitored by satellite (notably, the same status it was left in after last summer’s US-Israeli attacks, before this latest war). That may not reassure observers who fear that now Iran—its regime under severe stress, but expected to hold on to power—has more of an incentive to cross the nuclear weapons “threshold.” And as daunting a challenge as this stockpile of nuclear material is, it may not be the only unconventional weapons threat lurking in Iran. Indeed, Iran has acknowledged developing chemical weapons capabilities in the past. Its substantial biotechnology, pharmaceutical, and chemical industry, array of dual-use facilities, and cohort of scientists with relevant expertise and skills have long fueled concerns that it may not have given up on chemical weapons ambitions and that it may also have a latent biological weapons capability.

The United States, Israel, and other countries have remained suspicious. They continue to monitor Iran’s interest in dual-use chemicals, biological material, and equipment that could be used for development of offensive weapons capability and have designated numerous Iranian and other nationality individuals and entities has having violated nonproliferation and other sanctions.

While the situation is fluid, and with Trump sending ambiguous signals over the conflict’s endgame, it would be prudent to take stock of what is known and not known about the types and locations of dual-use chemical and biological materials of concern that may be present in Iran. Only then can policymakers make considered decisions about the relative benefits and costs of seeking them out or waiting for a good opportunity to look for them—and what to do if any are ultimately discovered.

Materials of concern. Following the 8-year-long war between Iran and Iraq, during which Iraq used mustard gas, tear gas, and tabun to devastating effect, Iran admitted to having developed a limited chemical weapons capability, but claimed not to have weaponized, stockpiled, or used any chemical weapons agent.

During the war, declassified US intelligence reports assess that Iran produced, weaponized, used, and stockpiled some combination of blood, blister, and choking chemical warfare agents. These included CS, a riot control agent, mustard gas, and phosgene, as well as possibly cyanide and nitrogen mustard. When the United States invaded Iran’s one-time adversary during that war, Iraq, in 2003, US troops found classified Iraqi correspondence about Iranian CW use during the 1980s war referencing the same agents as well as the manufacture of tabun and sarin nerve agents.

Iran is a state party to the 1972 Biological Weapons Convention (BWC) and the 1997 Chemical Weapons Convention (CWC). And in 2011, the United States acknowledged that senior Iranian officials publicly renounced the development, production, acquisition, and stockpiling of any weapons of mass destruction.

Starting in 2018, however, US administrations have certified to Congress in annual reports required by law that Iran is not in compliance with its chemical weapons treaty obligations. And since 2019, a companion report has consistently expressed “serious concerns” that Iran has “not abandoned its intention to conduct research and development of biological agents and toxins for offensive purposes.”

Throughout the 1990s and early 2000s, Iran sought to import a range of specific dual-use chemicals of concern, according to US Treasury sanctions reports, intelligence reports and arms control compliance reports compiled by the Wisconsin Project on Nuclear Arms Control; in addition to legitimate uses, the chemicals can be used in the production of nerve agents such as tabun, sarin, and VX.

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Some potentially concerning activities were not hidden in secret reports but visible in scientific journals.

In recent years, academics aligned with the Islamic Revolutionary Guard Corps (IRGC) and Ministry of Defense have published studies on the pharmaceutical-based agents fentanyl, a potent synthetic opioid pain-killer, and medetomidine, a non-opioid veterinary sedative, which have both legitimate medical uses and illicit applications as potential incapacitating or lethal chemical weapons agents.

Iranian military-aligned researchers have also reported researching and synthesizing a very small amount of the Novichok class of nerve agent that Russia used to poison Russian dissident Alexei Navalny in 2020 and retired KGB agent Sergei Skripal and his daughter in Salisbury, England, in 2018. The researchers cited a purpose of helping build up the knowledge base of the Organisation for the Prevention of Chemical Weapons (OPCW), the body that administrates the Chemical Weapons Convention.

Information on Iran’s possible biological materials of concern is sparser than on concerning chemical activities.

The National Council of Resistance of Iran (NCRI), part of an expatriate opposition group once designated by the United States as a terrorist organization but de-listed in 2012, has alleged that researchers associated with the IRGC and Ministry of Defense conducted research on plague, cholera and anthrax, highly pathogenic bacteria well known as biological weapons agents, and aflatoxin, a toxin weaponized by Iraq in the 1990s though considered of limited military utility. US compliance reports from 2019 to 2023 mention construction of a plant for pharmaceutical production of botulinum toxin, a deadly neurotoxin widely understood as a potential bioweapons agent due to its high potency at low doses. From 2019 to 2025, the US  reports refer to “open source reports” about [bioweapons]-relevant research on bioregulators conducted by universities and research centers affiliated with Iran’s military. Bioregulators are molecules produced naturally by the body such as neurotransmitters, hormones, and enzymes that regulate everything from mood to pain signals to vital functions. Biodefense researchers have highlighted the potential for misuse of these compounds as incapacitating or lethal bioweapons agents.

Locations. Should any stockpiles of chemical or biological agents or munitions exist, it is unclear where they might be stored. According to tables last published in the OPCW’s annual implementation report of 2015, Iran had fewer than 10 declared facilities handling chemicals covered by the chemical weapons treaty’s schedules 2 or 3, lists of toxic chemicals that pose varying degrees of risk to the purpose of the convention. Iran had around 100 other declarable and inspectable chemical facilities producing “discrete organic chemicals for purposes not prohibited by the Convention.” The Biological Weapons Convention has no inspection or verification regime, making it even more tricky to determine which of the universities and companies that make up Iran’s “sophisticated” biotechnology and pharmaceutical industry are of concern.

The Foundation for the Defense of Democracies (FDD), a Washington think tank, in March curated a “non-exhaustive” list of some 10 Iranian entities sanctioned by the United States and other countries for chemical weapons-related proliferation activities, some of which opposition groups allege have also engaged in bioweapons-related activities.

Notably, some facilities linked to these entities have been bombed or destroyed since the “12-day war” of 2025. Israel’s ambassador to the OPCW released a statement in July of 2025 saying the Shahid Meisami Research Complex was among this number. Analysis by independent researchers confirmed widespread damage. According to the FDD, Israel reportedly also targeted the research complex’s sponsor, the Organization of Defensive Innovation and Research (SPND). Separately, the Institute for the Study of War (ISW), an independent public policy research organization, has reported that in 2025 US and Israeli strikes hit the Imam Hossein University (IHU) in Tehran, suspected of working on Iran’s alleged chemical and biological weapons programs as well as its nuclear weapons program. Since the latest strikes started on February 28, the institute reports that the Malek Ashtar University (MUT), another site with suspected chemical and biological weapons connections, was hit and news reports indicate several explosions in Karaj, a city in western Iran where several suspected sites are located. These include the Defense Chemical Research Laboratory, a facility affiliated with co-authors of a 2022 paper on Novichoks, and Sina Industry, which the National Council of Resistance of Iran called “one of the most important biological and chemical laboratories of the Iranian regime,”  according to the Wisconsin Project’s Iran Watch.

Trump’s war on Iran: grave dangers and, at best, limited benefits

What next? Eliminating Iran’s vast complex of facilities through military means, many of which appear to have legitimate commercial, scientific, and medical purposes, might be possible through an extensive campaign. Eliminating the Iranian chemical and biological weapons knowledge reservoir, even if possible and desirable, seems likely to require radical regime change. While denying that regime change had been an objective, Trump in his Wednesday speech nonetheless argued it had been achieved—a conclusion belied by the evidence so far. Many Iranian regime leaders have been killed—only to be replaced by regime insiders, including the former supreme leader’s son. Further, regional specialists believe regime change will be exceedingly difficult given entrenched elites and power bases. Should the government manage to hold on to power, as expected, it could well decide to double down on chemical and biological weapons programs, which are easier to hide than a clandestine nuclear weapons effort. An international weapons inspection and destruction mission, such as the United Nations (UN) Special Commission deployed to Iraq following its invasion of Kuwait, seems unlikely in this case given discord on the Security Council, current US government attitudes toward the UN, and Iran’s resistance to International Atomic Energy Agency (IAEA) inspectors.

Nevertheless, the stresses on the Iranian government are severe and authoritarian regimes have collapsed suddenly and unexpectedly in the past, most recently in neighboring Syria. While Syria’s new government is working with the OPCW and international community to identify, declare, and eliminate remaining chemical weapons stockpiles, such sudden transitions generally raise the specter of “worst-case” proliferation scenarios where loss of control over unconventional weapons and related materials and expertise allows them to fall into the hands of non-state actors such as terrorists and criminals. The extensive scale of Iranian dual-use facilities, materials, and knowledge alone suggests that any new regime, ideally one that comes to power through a deliberate and well managed handover, will need to manage outflows of such items to prevent their acquisition by terrorists, criminal networks, and governments with nefarious interest in these capabilities. Even under the best of circumstances, such an effort requires considerable resources to devote to a steep learning and implementation curve.

To successfully address the proliferation threats posed by a country of 90 million people with large industrial and scientific complexes, global leaders in promoting and assisting in the implementation of the export control and border security requirements of international law, especially United Nations Security Council Resolution 1540 (2004), will likely need to embark on something akin to the  multi-year and multibillion-dollar cooperative threat reduction efforts sustained after the fall of the Soviet Union. In addition to eliminating dual-use biological weapons infrastructure and thousands of tons of bulk chemical agent, the Cooperative Threat Reduction Program provided civilian employment for thousands of former weapons scientists with dual-use knowledge.

Such an effort in Iran would include refocusing some facilities, setting up science programs or centers to attract those with relevant skills (and their families) to stay in Iran, establishing appropriate and effective legal and enforcement structures, and building compliance programs at an enterprise level. The international community, fortunately, does have at least one mechanism well versed in such efforts, the Group of 7 Global Partnership Against the Spread of Weapons and Materials of Mass Destruction (G7GP), a group founded in 2002 to coordinate and deliver major weapons of mass destruction threat reduction and security programming. Given existing commitments—to mitigating biological threats in Africa, countering disinformation, ensuring the complete elimination of Syria’s chemical weapons, and much more—a massive influx of resources and expansion of its programs would be required to address Iran’s legacy weapons of mass destruction programs.  But most important, a new regime will have many more immediate concerns, including establishing a new form of government, rebuilding the economy, rooting out corruption, and obtaining justice for those harmed under the old regime without enabling new atrocities. And as in those early post-Soviet years, the most important element of success will be building trust—perhaps the most difficult task of all.