Iran’s Chemical and Biological Weapons Programs: An Under-Appreciated Threat

As policymakers continue to focus on Iran’s nuclear and ballistic-missile programs, they aren’t paying enough attention to another danger—Tehran’s pursuit of chemical and biological weapons (CW and BW, respectively). The regime has operated—and may still carry on with—CW and BW programs, but much of the credible open-source reporting on them is several years old. The Trump administration has taken some good initial steps to publicize Iran’s CW program. The United States and other responsible nations should build on those steps by providing updated public assessments (redacting sensitive material, as necessary) of these programs, and announce and implement a policy focused on eliminating this threat.

Chemical Weapons (CW)

Initial Development until the Mid-1990s

Iran initiated its CW program during the Iran-Iraq War (1980–1988), during which Iraq repeatedly used CW. There are conflicting reports about whether Iran used CW during the war. A U.S. Defense Intelligence Agency declassified document from 1990 stated that "Iran used chemical weapons late in the war, but never as extensively or successfully as Iraq."

In November 1998, Mohammad R. Alborzi, director general of the Iranian foreign ministry, finally admitted that Iran had possessed CW near the end of the war, though he claimed the program was terminated after the end of the conflict. However, the U.S. Department of Defense reported that Tehran produced its first chemical agent in 1984, and it aggregately developed "a minimum several hundred tons of blister, blood, and choking agents."

A 1995 article in Jane’s Intelligence Review claimed Iran may then have had as much as 2,000 tons of chemical agents, including nerve agents. reports that:

Iran was believed to have manufactured weapons for blister, blood, and choking agents. It was also believed to be conducting research on nerve agents. Iran was working on developing a self-sufficient CW production capacity that included more effective nerve agents. Along with its shell and bomb delivery systems, Iran was also thought to have been producing CW warheads for its Scud missile systems. Its production capacity was estimated at as much as 1000 tons a year, with major production facilities located at Damghan, 300 km east of Tehran. Other facilities were believed to be located at Esfahan, Parchin and Qazvin.

Iran’s CW Program After Joining the Chemical Weapons Convention

Iran signed the Chemical Weapons Convention (CWC) in January 1993 and ratified it in November 1997, and the treaty came into force in December of that year. In joining the convention, Iran, like other states that are parties to the CVC, committed never to “develop, produce, otherwise acquire, stockpile or retain chemical weapons, or transfer, directly or indirectly, chemical weapons to anyone; to use chemical weapons; [t]o engage in any military preparations to use chemical weapons; [or] to assist, encourage or induce, in any way, anyone to engage in any activity prohibited” to other states parties to the CVC.

The Iranian government claimed it had destroyed its CW program before the treaty took effect. However, as the Nuclear Threat Initiative notes, Tehran has never publicly disclosed details of that program. Iran reported to the Organization for the Prohibition of Chemical Weapons (OPCW), which implements the CWC, that it had operated only one CW production facility, and had shuttered and destroyed it before the CWC took effect in December 1997. The OPCW has confirmed that the facility in question was destroyed.

However, the U.S. intelligence community (IC) has repeatedly reported that Tehran continues to operate a CW program. In 2000, John Lauder, then-director of the Director of Central Intelligence (DCI) Nonproliferation Center, testified before Congress that “We believe [Iran’s CW] program remains active despite Tehran's decision to ratify the Chemical Weapons Convention (CWC). Iran has a large and growing CW production capacity and already has produced a number of CW agents, including nerve, blister, choking, and blood agents. We believe it possesses a stockpile of at least several hundred metric tons of weaponized and bulk agent." A 2002 CIA report to Congress reached similar conclusions. The 2011 edition of that report made more limited findings, but did assess that Iran “maintains the capability to produce [CW] agents and conducts research that may have offensive applications” and “continues to seek dual-use technologies that could advance its capability to produce CW agents.”

The 2011 report also notes that Tehran “is capable of weaponizing CW agents in a variety of delivery systems.” These options, according to open-source reports from Jane’s and other sources, may include artillery shells, mortar rounds, aerial bombs, mines, unmanned aerial vehicles, and even chemical warheads for Scud, Shahab, and cruise missiles.

Recent Developments

In 2018, after years of international quiet about Iran’s CW program, the U.S. made headlines by accusing Iran of seeking “Central Nervous System-Acting Chemicals” for offensive weapons. Ambassador Kenneth Ward, U.S. permanent representative to the OPCW, also said Tehran had repeatedly failed to fully disclose its CW activities to that organization. As examples, Ward claimed Iran had failed to disclose: its transfer of CW to Libya in the 1980s; all of its riot-control agents, some of which Tehran had marketed at defense expos; and its capability to fill chemical weapons production facilities.

Further, the U.S. Department of State stated in an April 2019 report that Iranian military-controlled facilities, Imam Hossein University (IHU) and Malek Ashtar University (MAU), have researched incapacitating chemical agents. Published Iranian articles have cited weaponizing applications of pharmaceutical-based agents (PBAs), including the powerful opioid fentanyl. The report added that IHU’s chemistry department had sought kilograms of medetomidine—an incapacitating sedative it has researched—from Chinese sellers. Nonproliferation analyst Peter Brookes of the Heritage Foundation has written that such PBAs “could also be furtively introduced into water, food, or agricultural systems, or could be aerosolized.”

Foreign Assistance

Foreign governments, including Russia and China, have provided indispensable aid to Iran’s chemical-weapons program. Such assistance has included production plants and equipment, technologies, and chemical-agent precursors.

For instance, as noted by Anthony Cordesman and Adam Seitz, “the [U.S. Central Intelligence Agency (CIA)] reported that Chinese entities were selling Iran chemical warfare–related chemicals between 1997 and 1998.” China also sold Iran 500 tons of phosphorus pentasulfide, a dual-use chemical that can be used to produce the VX nerve agent. In 2000, the aforementioned John Lauder, then director of the DCI Nonproliferation Center, testified before Congress that “Numerous Russian entities have been providing Iran with dual-use industrial chemicals, equipment, and chemical production technology that could be diverted to Tehran's offensive CW program.” Lauder cited as an example that in 1999, “Russian entities provided production technology, training, and expertise that Iran could use to create a more advanced and self-sufficient CW infrastructure.”

Other countries also assisted Iran’s CW program. As Cordesman and Seitz note, “The United States accused German firms of selling dual-use materials and technology to Iran during the 1980s.”

India also provided aid. “In 1989, the State Trading Company of India admitted that it had sold Iran over 60 tons of thionyl chloride (a nerve agent precursor) and that its supplier was planning to ship an additional 257 tons of the chemical to Iran.” In 1997, India also agreed to build an advanced chemical plant near Tehran.

Even an American company got in on the action, in violation of U.S. export-control laws. In 1991, the Maryland-based chemical manufacturer Alcolac pled guilty to indirectly selling 120 tons of the dual-use mustard gas–precursor thiodiglycol to Iran via the German company Colimex GmbH and Co.

That said, Iran has long sought to be able to develop CW indigenously. Director Lauder testified in 2000 that “Tehran's goals for its CW program for the past decade have been to expand its production capability and stockpile, reach self-sufficiency by acquiring the means to manufacture chemical production equipment and precursors, and diversify its CW arsenal by producing more sophisticated and lethal agents and munitions.”

In April 2020, the U.S. again certified, for the aforementioned reasons, that Iran was not in compliance with the CWC.

Biological Weapons (BW)

A Cloud of Uncertainty

Iran ratified the Biological Weapons Convention (BWC) in 1973, during the rule of the shah, and the Islamic Republic denies the existence of a BW program. However, determining the existence, size, and scope of Iran’s BW programs is harder than making such determinations regarding CW, nuclear-weapons, and missile programs.

As analysts Anthony Cordesman and Adam Seitz note, BW programs can easily be hidden because they require small-scale equipment and dual-use materials; such programs can be housed in medical, biotech, and research organizations and facilities, including universities; and BW agents are easier and less expensive to make than CW agents and nuclear materials. “The fact of the matter is that any nation with even modestly sophisticated biopharmaceutical industrial capabilities is capable of producing biological agents,” Cordesman and Seitz write. And Iran’s capabilities are more than modestly sophisticated—it enjoys one of the larger biotech sectors in the developing world.

Worse still, keeping dual-use equipment out of Tehran’s hands is difficult because “the steady expansion of civil biotechnology, food processing, and pharmaceutical activities makes dual-use equipment commercially available that can be used to produce even the most advanced biological agents and a combination of Iran’s use of covert purchasing networks and steadily weakening controls – particularly over used and surplus equipment – have further weakened already weak export control efforts.”

Finally, the line between defensive and offensive BW programs is very unclear, for developing defenses against a given biological weapon requires possessing it.

Consequently, as Cordesman and Seitz assert, it is difficult to know what actual BW work Iran is doing, as opposed to its BW capabilities.

Possible Past and Ongoing BW Efforts

As with CW, the U.S. has suspected that Iran first developed a BW program during its war with Iraq from 1980 to 1988. In 1982, U.S. government officials began holding briefings claiming Iran had imported cultures from Europe and had begun working to make mycotoxins, simple biological agents, at different research facilities. Experts believed the BW program was controlled by Iran’s Islamic Revolutionary Guard Corps (IRGC).

A blatant indicator of the Iranian government’s intention to develop BW is its recruitment of scientists who worked on the Soviet Union’s germ-warfare program. Two of the scientists told the New York Times that Tehran outright asked them to assist Iran in producing BW.

During the 1980s and 1990s, reports continued to emerge of Iranian procurement of BW-suitable technology and materials—fungus strains from Canada and the Netherlands in 1989; of advanced BW technology from Switzerland and containment equipment and technology from Germany in 1993; dual-use technology from India and China in 1996; and so forth. Leading centers for biotech and medical research—and therefore likely candidates for BW research and development—are the Louis Pasteur Institute, the National Research Center of Genetic Engineering and Biotechnology (NRCGEB), and the Razi Institute for Serum and Vaccines. The Nuclear Threat Initiative notes that the seemingly benign activities undertaken by those institutes have dual-use applications. “For example, the NRCGEB's expertise in recombinant DNA technologies, genetic engineering, and DNA vaccine production could conceivably be utilized to research methods for increasing the virulence or resistance of select pathogens, and equipment for mass-producing vaccines and antiserums at the Pasteur Institute could be utilized to mass-produce biological weapons as well.”

Bottom-Line U.S. Government Assessments

The U.S. government has long assessed that Iran enjoys BW-producing capabilities at the very least, and is or may be operating a BW program itself.

For example, in 1996, the CIA concluded that “Iran holds some stocks of biological agents and weapons. Tehran probably has investigated both toxins and live organisms as biological warfare agents. Iran has the technical infrastructure to support a significant biological weapons program with little foreign assistance.”

In 2000, DCI Nonproliferation Center Director John Lauder testified to Congress that “Iran is pursuing both civilian biotech activities and a biological warfare (BW) program,” that its BW program was then “in the late stages of research and development,” and that Iran “already holds some stocks of BW agents and weapons.”

In 2003 and 2005 reports, the State Department stated that, “Iran has an offensive biological weapons program in violation of the BWC. Iran is technically capable of producing at least rudimentary biological warheads for a variety of delivery systems, including missiles.” In 2011, then–Director of National Intelligence James Clapper stated that “Iran probably has the capability to produce some biological warfare (BW) agents for offensive purposes, if it made the decision to do so. We assess that Iran has previously conducted offensive BW agent research and development. Iran continues to seek dual-use technologies that could be used for BW.”

More recent reports on Iran’s BW pursuits have reached mixed conclusions regarding the status of Iran’s BW program. In 2015, the Department of State reported that “available information indicated that Iran continues to engage in dual-use activities with BW applications, but it is unclear if these activities were conducted for purposes inconsistent with the BWC.” In 2019, the State Department questioned Iran’s compliance with the BWC, assessing that “Iran has not abandoned its intention to conduct research and development of biological agents and toxins for offensive purposes. Also, Iran maintains flexibility to divert, upon leadership demand, legitimate research underway for biodefense and public health purposes to a capability to produce lethal BW.” State added that it was complicated to evaluate Iranian compliance because the U.S. still cannot distinguish between Iranian “public health research and biodefense activities from those that are prohibited under the BWC,” but highlighted Iran’s “sophisticated toxin research and production” and “reporting suggesting a capability to produce lethal agents on demand.” State reached similar conclusions in April 2020.

Next Policy Steps

The Trump administration has rightly called out Iran for its continuing CW activities and non-disclosure of such activities to the OPCW. The U.S. should also engage in vigorous diplomacy to encourage foreign governments to pay more attention to Iran’s CW program. Further, if Washington has intelligence on Iranian CW sites, it should consider seeking a “challenge inspection” of suspected Iranian CW program sites by the OPCW, pursuant to the CWC, and ask other countries to join the U.S. in this request. No state has ever requested a challenge inspection, so this unprecedented step would underscore the CW danger Iran poses

The U.S. intelligence community should also issue updated reporting on Iran’s BW pursuits, if only to increase awareness of this issue among U.S. and international policy-makers. This reporting should, to the extent possible, distinguish Tehran’s BW capabilities from any active measures to produce or to support production of BW.

Finally, Washington should better integrate Iran’s CW and BW threats into America’s holistic policy on Iran. For example, the Trump administration has issued 12 demands of the Iranian regime as prerequisites for the end of U.S. sanctions and restoration of normal diplomatic relations with Iran. Secretary of State Mike Pompeo stated the demands cover the “scope of the malign behavior of Iran,” but they do not. The U.S. should issue a 13th demand: a full accounting and dismantlement of Tehran’s CW and BW programs.

As the Syrian regime has shown in recent years, CW fall under the category of weapons of mass destruction for a reason—because they can massively destroy human lives. The same holds true for BW. It is past time for the U.S. and other responsible international actors to act with seriousness to ensure that Iran, one of the world’s worst rogue regimes, cannot use or threaten the use of such weapons to advance its malign agenda.