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Part I: “We attacked them with chemical weapons and they attacked us with chemical weapons”: Iraqi Records and the History of Iran’s Chemical Weapons Program

The first of a three-part article addressing the legacy of chemical weapons use in the Iran-Iraq War and Iran’s chemical weapons program

During the Iran-Iraq War, the Iraqi military under the regime of Saddam Hussein’s Baʿth Party employed chemical weapons on a massive scale, targeting Iranian troops, border villages in western Iran, domestic Iraqi Kurdish rebel groups, and civilian inhabitants of northern Iraq. According to Iraq’s own declarations to the United Nations Special Commission (UNSCOM), between 1983 and 1988, it used 1,800 tons of mustard gas, 140 tons of Tabun nerve gas, and 600 tons of Sarin nerve gas, delivered by way of 19,500 aerial bombs, 54,000 artillery shells, and 27,000 short-range rockets.[1] Iraq’s defensive military reliance on these weapons, followed by their integration into offensive operations in the latter phases of the war with the Islamic Republic of Iran between 1986 and 1988, has been well documented and benefited greatly from the availability of internal Iraqi records on the subject.[2]

The growing declassification of US Central Intelligence Agency (CIA) and Defense Intelligence Agency (DIA) records has confirmed major details and added new information to the public record as well. The decision by President Ronald Reagan’s administration to support Iraq in its war against Islamic Revolutionary Iran has long received academic and political interest. Against the backdrop of Saddam’s decision to invade and occupy Kuwait on August 2, 1990, prior US support for Iraq and its use of chemical weapons against Iran, raised questions and fueled claims that Saddam had been encouraged or emboldened by the United States, and that the latter in turn failed to deter him.[3]

While these debates had immediate political salience in the context of Republican-Democrat politics, the greater availability of Iraqi and US internal records has outlined a far more complicated picture. On the one hand, the Reagan administration and US intelligence community possessed far greater detailed knowledge of Iraq’s use of chemical weapons than they let on. On the other hand, the United States had limited to no ability to influence Iraq on its use of chemical weapons during the Iran-Iraq War. Furthermore, Saddam’s longstanding distrust and suspicion of the United States, even during the period of Washington’s support for Baghdad, casts doubt on the US ability to have deterred him, to say nothing of encouraging his regional ambitions. One of the many benefits of access to internal Iraqi records has been to enable recent scholarship to decenter the United States or the West more broadly as the primary driver of events during the Baʿthist period of Iraq’s modern history, shifting the focus instead to the Baʿthist regime and Saddam himself.

In contrast to Iraq, Iran’s chemical weapons program and possible battlefield use of chemical weapons on a limited scale during the latter phases of the Iran-Iraq War remain controversial and debated more than three decades later.[4] Despite its reactive origins to Iraq’s chemical weapons use, Iran’s chemical weapons program is relevant to subsequent historical developments and even current events, such as renewed international concern about the country’s nuclear program. Lingering questions of past Iranian proliferation of chemical weapons are likely not on the agenda as efforts to revive the 2015 nuclear deal appear to have reached their final stage. Nevertheless, past Iranian behavior with chemical weapons may offer clues as to how an Iran possessing nuclear weapons could act on the regional and global stages.

However, one of the largest obstacles impeding efforts to study the history of Iran’s chemical weapons program has been the lack of open research access to internal Iranian records.[5] Additionally, questions about Iran and chemical weapons have been inexorably connected to contemporary Iraqi efforts to create the appearance before the United Nations that both Iran and Iraq were using chemical weapons on a comparably large scale, along with blaming Iran for the Halabja massacre of Iraqi Kurds.[6] These claims were in turn echoed by some US intelligence officers and political officials then assisting the Iraqi military in its war against Iran, along with some members of the western media, asserting that both Iran and Iraq used chemical weapons at Halabja, or casting doubt on the genocidal nature of Iraq’s Anfal campaigns in northern Iraq. The afterlife of the claim that Iran was partially or entirely responsible for the gassing of Halabja was peculiar, invoked by Edward Said in criticizing US policy during the 1990-1991 Gulf War, and later cited by one of the Central Intelligence Agency analysts originally associated with it in opposition to looming U.S.-led invasion of Iraq in 2003.[7] The complexities of the Middle East’s politics are clearly rivaled by those of the politics surrounding US Middle East policy. In the case of the latter, it may be possible for one to offer a fundamentally sound policy proposal for all the wrong factual reasons.

The Libya Connection

Previous works addressing the subject of Iran’s chemical weapons program have noted the potential of Iraqi records captured during the 2003 War for containing evidence of Iran’s development of chemical weapons, battlefield usage, and proliferation to its allies, such as when Libyan rebels discovered two caches of mustard gas munitions, some 517 155-millimeter artillery rounds and eight aerial bombs, with Persian markings in 2011 and 2012. This surprising discovery, made by rebels fighting to overthrow the regime of Colonel Muʿammar al-Qaddafi, would provide a window into one of the more obscure regional episodes in the Iran-Iraq War. If not for the Persian markings, the rebels likely would have assumed the munitions were products of Libya’s own chemical weapons program. Fortunately for researchers, the identification of the munitions provided arguably the most important clue to date on the history of Iran’s chemical weapons program.

While the artillery shells could have in theory been captured Iraqi munitions packaged into Iranian boxes before being shipped to Libya, as both the Iraqi and Iranian militaries used 155-millimeter artillery, it is unclear how this could have been the case for the aerial bombs, as Iranian ground forces never overran Iraqi military airfields during the Iran-Iraq War. Furthermore, considering the lengths Iran went to in attempting to draw international attention to Iraq’s chemical weapons use, it is unclear why it would have traded captured Iraqi chemical weapons to Libya instead of presenting them as evidence to the United Nations Security Council investigations it requested on the subject, which routinely visited Iran from 1984 to 1988.[8] Since Iranian officials led the UN teams to sites where they investigated expended Iraqi chemical rounds, had Iranian forces actually captured a large cache of Iraq chemical rounds, it seems reasonable to suppose they would have saved at least one round to present to the UN. As will be seen, the episode contains valuable insights into the proliferation of chemical weapons, along with military cooperation between Iran and Libya, one of the former’s few allies other than Syria and North Korea. The Iraqi intelligence documents on the subject offer independent confirmation, along with additional details, that together help in piecing together the valuable reporting of journalists who have covered aspects of this story between 1987 and 2014.

In December 2003, following the US-led overthrow of Saddam Hussein’s regime earlier that year, Qaddafi announced he would give up Libya’s nuclear and chemical weapons programs. United Nations teams were then sent to Libya to dismantle chemical and nuclear facilities on-site. Components from the nuclear program were shipped to the Oak Ridge National Laboratory in Tennessee. Dismantling Libya’s chemical weapons program, which began during the 1980s, proved time-consuming. The UN inspection unit assigned with the task, the Organization for the Prohibition of Chemical Weapons, was still at work when the uprising against Qaddafi’s regime began in February 2011. As a result, the organization was forced to suspend its efforts, despite having destroyed only half of Libya’s chemical stocks by that time.

Following the overthrow of Qaddafi’s regime and killing of the Libyan dictator by rebels in October 2011, resuming the destruction of his chemical arsenal took on greater importance in view of the growing presence of militias and jihadist groups linked to al-Qaeda in the country. As Libya under the Transitional Government teetered toward civil war, the last chemical weapon shell was reportedly destroyed on January 26, 2014.

Media coverage at the time hinted that the last munitions to be destroyed were the Iranian ones first discovered by rebels in November 2011. Writing for the New York Times on February 2, 2014, Eric Schmitt noted that the discovery of the two caches of unspecified munitions in question had come as a surprise in November 2011 and February 2012, and were not previously declared by Qaddafi in 2003. Furthermore, “unlike the majority of Libya’s mustard agents, which were stored in large, bulky containers, the new caches were already armed and loaded into 517 artillery shells, 45 plastic sleeves for rocket launchings and eight 500-pound bombs.” Given the fact that the munitions were not products of Libya’s chemical weapons program, Qaddafi likely decided in December 2003 or sometime later that declaring them would implicate his Iranian ally and that it was better to leave them buried deep in the southern Libyan desert. However, the events of 2011 inadvertently ensured that this chapter in Iranian-Libyan relations and proliferation would not remain obscured by the sands of time. 

The discovery of the mustard gas shells and aerial bombs beginning in November 2011 led the administration of President Barack Obama to order an intelligence probe. In the Washington Post, R. Jeffrey Smith and Joby Warrick reported: “‘We are pretty sure we know’ the shells were custom-designed and produced in Iran for Libya, said a senior U.S. official, one of several who spoke on the condition of anonymity because of the sensitivity of the accusation.” Elsewhere in the article, it appeared the administration was still piecing together the full story. Another unnamed US official suggested that Iran may have sold the munitions to Libya following the end of the Iran-Iraq War, whereas another official added, “These were acquired over many years.” At the time of the article’s publication, administration and intelligence officials were following the case back to the 1980s but appeared not to have yet connected all the dots, some of which existed in the public record. In the event either group did trace the story back to Iran in the 1980s, any concerns that may have been raised appear not have affected the Obama administration’s pursuit of negotiations about Iran’s nuclear program between 2013 and 2015.

In 1985, rather than Iranian proliferation, US officials were concerned that the opposite move was taking place: Iran was trying to obtain chemical weapons from Libya. As the Boston Globe reported: “intelligence sources say Iran now appears to possess poison gas, although it is not known whether it was supplied by Libya, along with Scud missiles, or procured in Iran.” Subsequently, US officials appear to have had clearer indications of a potential Iran-Libya arms deal by September 1987. Quoting a Reagan administration official, the Washington Post reported that “the Soviets and the Americans, in a rare example of U.S.-Soviet cooperation, had jointly pressed Libyan leader Moammar Gadhafi to not swap weapons with Iran.”

Reports that Libya was trying to trade sophisticated Soviet-made sea mines to Iran in exchange for chemical weapons were deeply concerning for the Reagan administration. The mines would be immediately useful for Iran in the “tanker war” theater of its conflict with Iraq, in which both belligerents attacked neutral shipping conducting commerce with the other in the Persian Gulf. The US Navy was becoming increasingly involved in escorting convoys and providing protection from Iranian attacks. Fears of Iranian mining capabilities were not unfounded. On April 14, 1988, an Iranian mine would nearly sink the guided missile frigate USS Samuel B. Roberts. However, at the time of the Washington Post article, the US and Soviet officials may have pressured Qaddafi too late. The same article noted that Chad had recently complained about Libyan forces using chemical weapons against its troops. A senior Reagan administration official noted Chad’s complaint, but added, “‘to our knowledge,’ Libya does not have chemical warfare capability.”

 A little over three months later, the story would return to news headlines and bring confirmation that the Iran-Libya deal arms deal had taken place. First, an Associated Press article, reporting on coverage in the British Independent, noted, “Iran agreed to provide chemical weapons to Libya in exchange for advanced Soviet-made Scud-B missiles, which have been used in Iranian attacks on the Iraqi capital.” The Independent quoted unidentified sources in Tehran and Tripoli as saying, “Iran has developed three new types of chemical mortar shells and rockets for use against ships, tanks, and troops.” The breaking of this news coincided with successive contradictory statements by Iranian Prime Minister Mir-Hussein Mousavi. Mousavi had recently stated Iran was producing “sophisticated offensive chemical weapons,” before walking that statement back. Following a cabinet meeting, he was quoted as telling reporters, “The Islamic Republic is capable of manufacturing chemical weapons and possesses the technology. But we will produce them only when Islam allows us and when we are compelled to do so.”

Shortly thereafter, writing for the New York Times on December 24, 1987, Michael R. Gordon reported that “American officials said that in recent months Libya appeared to have provided Soviet-made mines to Iran in exchange for chemical weapons,” which Libya in turn attempted to use for its military intervention in Chad. Starting in 1978, Qaddafi had intervened on multiple occasions in Chad’s civil war, initially aiming to annex and create a base for further operations in the mineral-rich Aouzou Strip on Libya’s southern border. By the late-1980s, with the assistance of the United States, France, and Zaire, most Chadian factions united against the Libyan presence, pushing Qaddafi’s campaign to the brink of defeat. With French support, Chadian forces carried the fighting across the border into Libya. Upon learning of a surprise attack on a Libyan base, Qaddafi ordered his forces to drop Iranian-supplied chemical weapons bombs on Chadian forces. Joshua Sinai, a senior analyst for the Library of Congress’s Federal Research Division, concluded, “Although this use of chemical weapons was not extensive enough to be militarily decisive, it set an ominous precedent.”

In the trade of chemical weapons by Iran for sea mines from Libya, Iraq arguably had less to fear if sea mines were indeed the trade item and not Scud missiles. Iraq had a small navy and been effectively cut off from the Persian Gulf by Iran since the early days of the war in 1980. Iranian chemical weapons could have been deployed on any number of battlefields against Iraqi forces, unlike sea mines. While Iraq’s General Military Intelligence Directorate made note of the NYT article,[9] their own investigation of the subject revealed a similar but slightly different transaction that was more concerning to the Iraqis. Citing information shared with them by Egyptian intelligence and echoing the Independent and AP coverage, they reported the existence of “an agreement signed between Iran and Libya in late 1987, according to which Libya will receive chemical weapons from Iran who will get Russian-made Scud-B missiles in return.”[10]

Unlike sea mines, Scud-B missiles in Iranian possession could immediately be deployed in the “war of the cities” theater of the Iran-Iraq War, where overwhelmingly Iraq, but ultimately both belligerents fired ballistic missiles at the other’s civilian population centers. Iran enjoyed geographic proximity to Iraq’s urban areas, but was at a disadvantage to Iraq’s superior ballistic missile arsenal and technology. During the conflict, Iran did acquire some Scud-B missiles and begin domestic production, the origins to what is today the region’s most extensive and sophisticated ballistic missile program. With respect to the Iran-Libya arms deal, the commonality between US officials, Western news reporting, Iraqi intelligence, and Egyptian intelligence is that Iran sent chemical weapons to Libya. The available documentation is not sufficient for determining whether Iran received sea mines, Scud-B missiles, or both. However, it is striking that US and Iraqi intelligence each saw Iran receiving what would be most dangerous to their own forces or interests.

In addition to its value to the historical record, this episode has import to ongoing talks between Iran, the United States, Russia, China, France, Britain, and the European Union about returning to the Joint Comprehensive Plan of Action (JCPOA), or forging a new agreement to replace it. Although Iran ratified the Chemical Weapons Convention in 1997, the US State Department under Secretary Mike Pompeo and the administration of President Donald Trump certified Iran as non-compliant in November 2018. This announcement came after President Trump officially ended US participation in the JCPOA on May 8, 2018, following Iran’s refusal to negotiate a replacement deal that went beyond its nuclear program and also addressed its ballistic missile program, support for armed groups in the Middle East, and threats to neighboring countries and US regional interests.

The Chemical Weapons Convention non-compliance certification in November 2018 coincided with the reimposition of sanctions against Iran by the Trump administration, opening moves in its “maximum pressure campaign.” Then, in June 2020, the State Department report on compliance with the prohibition and destruction of chemical weapons listed Iran’s failure to declare the transaction that sent artillery shells and aerial bombs filled with mustard gas to Libya in 1987 as a top reason for its non-compliant certification. In this regard, Iran had followed in the footsteps of Libya’s Qaddafi in failing to disclose the transaction. According to the State Department report, “in light of the discovery of chemical-filled artillery projectiles and aerial bombs, the U.S. assesses that Iran filled and possessed chemical weapons.” The report goes on to address the claims that Iran used chemical weapons late in its war with Iraq, mentioning the use of chemical mortar rounds near Basra in 1987. Despite the political transition from the Trump administration and eagerness of President Joe Biden’s administration to renew diplomatic talks, Iran was re-certified as non-compliant by the US State Department under Secretary Antony Blinken on all these same grounds in April 2021. 

The surprise discoveries made by Libyan rebels in November 2011 and February 2012 thus confirmed the rumored trade for chemical weapons between Iran and Libya first reported in 1987. The expedited destruction of the mustard gas shells and bombs in 2014 was foregrounded by fears of further proliferation of the weapons to militias and jihadist groups on the eve of Libya’s descent into civil war. Although this episode may be small in the context of the Iran-Iraq War, as the State Department reports indicate, it remains a sticking point in US-Iran relations and may inform the concerns of analysts and US policymakers with respect to Iran’s nuclear weapons program and the threat of proliferation in the present day.

The next part of this article will move away from the desert sands of southern Libya and northern Chad, returning to the battlefields of the Iran-Iraq War. It is there that Iraq’s use of chemical weapons, Iraqi claims of Iran’s use of chemical weapons, the official statements of both Iraqi and Iranian political leaders, and United Nations investigations will be the basis of the second installment.


[1] Central Intelligence Agency, “Transmittal Message,” Comprehensive Report of the Special Adviser to the DCI on Iraq’s WMD, September 23, 2004, vol. 3, 5, 10; also cited in Kevin M. Woods, David D. Palkki, and Mark E. Stout (eds.), The Saddam Tapes: The Inner Workings of a Tyrant’s Regime 1978-2001 (New York: Cambridge University Press, 2011), 220-221.

[2] See Chapter 6., “Special Munitions” in Woods, Palkki, and Stout, The Saddam Tapes, 219-253, Williamson Murray and Kevin M. Woods, The Iran-Iraq War: A Military and Strategic History (New York: Cambridge University Press, 2014), 268-269, and Pierre Razoux, The Iran-Iraq War (Cambridge, Massachusetts: The Belknap Press of Harvard University Press, 2015), 441.

[3] For perhaps the best example, see Bruce W. Jentleson, With Friends Like These: Reagan, Bush, and Saddam, 1982-1990 (New York: W.W. Norton & Company, 1994). Jentleson was a foreign policy adviser to Senator Al Gore in 1987 and 1988. He subsequently served in the administration of President Bill Clinton as special assistant to the director of the Policy Planning Staff at the State Department.

[4] The most detailed treatments of the subject are Michael Eisenstadt, “What Iran’s Chemical Past Tells Us About Its Nuclear Future,” Washington Institute for Near East Policy Research Notes, No. 17 (April 2014), 1-20, Chapter 7, “Iran and the Use of Gas” in Joost R. Hiltermann, A Poisonous Affair: America, Iraq, and the Gassing of Halabja (New York: Cambridge University Press, 2007), 148-182, Dany Shoham, “Image vs. Reality of Iranian Chemical and Biological Weapons,” International Journal of Intelligence and Counterintelligence, Vol. 18, No. 1 (2005), 89-141, Jean Pascal Zanders, “Iranian Use of Chemical Weapons: A Critical Analysis of Past Allegations,” Center for Nonproliferation Studies Briefing Series, March 7, 2001,, and Gregory F. Giles, “The Islamic Republic of Iran and Nuclear, Biological, and Chemical Weapons,” in Peter R. Lavoy, Scott D. Sagan, and James J. Wirtz (eds.), Planning the Unthinkable: How New Powers will use Nuclear, Biological, and Chemical Weapons (Ithaca, New York: Cornell University Press, 2000), 79-103.

[5] While this is also the case with official Iranian records on the Iran-Iraq War more broadly, state-sponsored histories of the conflict regularly include copies of select documents. For the most extensive research to date using these sources, see Annie Tracy Samuel, The Unfinished History of the Iran-Iraq War: Faith, Firepower, and Iran’s Revolutionary Guards (New York: Cambridge University Press, 2021).

[6] The authoritative single-volume study on this subject and the ensuing controversy is Hiltermann, A Poisonous Affair. See also David D. Palkki and Lawrence Rubin, “Saddam Hussein’s role in the gassing of Halabja,” The Nonproliferation Review (2021), 1-15.

[7] The claim even influenced some academic criticism of the 2003 Iraq War. For example, see Sharat G. Lin, “US Lying About Halabja: Justifying the Invasion of Iraq,” Economic and Political Weekly, Vol. 42, No. 36 (September 8-14, 2007), 3625-3632.

[8] The first investigative report was released by the United Nations Security Council on March 26, 1984, and the last on August 19, 1988. For example, see, “Report of the Mission Dispatched by the Secretary-General to Investigate Allegations of the Use of Chemical Weapons in the Conflict Between the Islamic Republic of Iran and Iraq,” United Nations Security Council, August 19, 1988, 5-12. These sources are available online courtesy of the United Nations Digital Library.

[9] Conflict Records Research Center (CRRC), SH-MISC-D-000-959, “The Use of Chemical Weapons by Iran in its War with Iraq,” March-June 1988.

[10] CRRC, SH-GMID-D-000-898, “General Military Intelligence Directorate Memos Discussing Iranian Chemical Weapons Capability,” October 1987-September 1988.

About the Author

Michael Brill

Global Fellow;
Ph.D. Candidate, Department of Near Eastern Studies, Princeton University

Michael P. Brill is a Ph.D. candidate in the Department of Near Eastern Studies at Princeton University, where his research focuses on Ba'thist Iraq.

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