- Weapon Program Background Report
November 1929: Iran accedes to the Geneva Protocol for the Prohibition of the Use of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare.
September 1980: The Iran-Iraq War begins.
1983: According to a U.S. Defense Intelligence Agency study, Iran's offensive chemical weapon program begins in response to Iraq's use of chemical agents on the battlefield. The DIA believes that the program began under the auspices of the Islamic Revolutionary Guard Corps (IRGC), with some assistance from the Ministry of Defense.
November 1983: In a communication to the United Nations, Iran alleges that it has been targeted with chemical weapons by Iraq.
April 1984: The U.N. Security Council releases a report confirming that aerial bombs with mustard gas and tabun, a nerve agent, have been used against targets in Iran.
1985: The Australia Group forms in reaction to the U.N. documented use of chemical weapons in the Iran-Iraq War. Member states pledge to harmonize export licensing for chemicals used in the manufacture of chemical weapons.
1987: Iran is able to deploy limited quantities of mustard gas and cyanide against Iraqi troops using artillery shells, according to the U.S. Department of Defense.
1987: Iran transfers chemical weapons to Libya in exchange for naval mines, according to U.S. intelligence sources.
July 1987: The United States imposes controls on the export of eight chemicals, useful in the production of chemical weapons, to Iran, Iraq, and Syria.
May 1988: U.N. Security Council Resolution 612 is unanimously adopted, condemning the use of chemical weapons in the Iran-Iraq war and calling on both sides to adhere to the Geneva Protocol.
July 1988: Iraq turns over 141 chemical weapon mortar rounds, which they claim are Iranian, to the United Nations. U.N. investigators later reveal that the ammunition crates tested positive for mustard gas.
August 1988: Iran-Iraq war ends in a stalemate.
1989: Media reports reveal that an Iranian diplomat arranged for a West German firm to purchase 210 tons of thiodiglycol from a supplier in the United States and then ship it to Iran in three installments, from March 1987 to April 1988. Reportedly, two shipments totaling 90 tons successfully made it to Iran, while the third 120 ton shipment was intercepted by U.S. Customs agents. Thiodiglycol is a chemical weapon (blister agent) precursor.
March 1989: Iran allegedly acquires 60 tons of thionyl chloride from India's government-run State Trading Corporation. Thionyl chloride is a chemical weapon (nerve agent) precursor.
March 1990: A U.S. Defense Intelligence Agency report confirms Iran's indigenous chemical weapon production capability, including sulfur mustard gas.
1991: During an inspection at Iraq's Muthana State Establishment, U.N. inspectors find 165 81-mm mortars filled with sulfur mustard that Iraq claims are Iranian-origin.
October 1992: The United States passes the Iran-Iraq Non-Proliferation Act. This act opposes the "transfer to Iran or Iraq of any goods or technology [that] could materially contribute to either country's acquiring chemical, biological, nuclear, or destabilizing numbers and types of advanced conventional weapons."
January 1993: Iran signs the Chemical Weapons Convention (CWC).
November 1994: The United States sanctions one Austrian, one Australian, and one German citizen under the Arms Export Control Act and the Export Administration Act of 1979, allegedly for supplying Chinese chemicals to Iran.
January 1995: German intelligence reportedly indicates that at least three Indian companies, including Tata Consulting Engineering, Transpek, and Rallis India, helped Iran equip a factory capable of producing the nerve agents sarin and tabun.
February 1995: The United States sanctions three entities operating in the Asia-Pacific region for chemical weapon proliferation under the Arms Export Control Act and the Export Administration Act of 1979, allegedly for supplying Chinese chemicals to Iran.
February 1996: The Central Intelligence Agency (CIA) estimates that Iran has one of the largest chemical warfare programs in the developing world. Its arsenal of several thousand tons of chemical agents includes sulfur mustard, phosgene, and cyanide, which can be delivered using artillery, mortars, rockets, aerial bombs and perhaps Scud warheads. The CIA also estimates that Iran is capable of producing an additional 1,000 tons of chemical agent each year.
1997: In its report to Congress on worldwide proliferation, the CIA says Iran has "manufactured and stockpiled chemical weapons, including blister, blood, and choking agents and the bombs and artillery shells to deliver them," and has continued to import "material related to chemical warfare" from China.
1997: India reportedly signs a multi-million dollar contract to build an advanced chemical plant in Qazvim near Tehran.
January 1997: U.S. authorities thwart a conspiracy led by Iranian national Abdol Hamid Rashidian and American national Henry Joseph Trojack to ship impregnated alumina, which can be used to make components of the nerve agents VX and GB, from the United States to Iran.
May 1997: The United States imposes sanctions on seven Chinese entities and one Hong Kong entity under the Arms Export Control Act and the Export Administration Act of 1979, for "knowingly and materially" contributing to Iran's chemical weapon program. The sanctioned entities include Chinese national Chen Qingchang, who is subsequently sanctioned by the United States on several occasions for ongoing chemical weapon-related transfers to Iran.
May 1997: Israeli national Nahum Manbar is indicted in Israel on charges of attempting to sell technology and equipment for the production of mustard gas and nerve agents to Iran from 1990 to 1994.
November 1997: Iran ratifies the CWC.
1998: China reportedly sells Iran 500 tons of phosphorous pentasulfide, which is a chemical precursor for the nerve agent VX.
May 1998: At the Third Conference of States Parties to the CWC, Iran acknowledges for the first time that it had a chemical weapon program during the Iran-Iraq war, but claims that the program was terminated after the war. The U.S. State Department assesses that Iran has not submitted an accurate declaration under the Convention and claims that Iran is attempting to "retain and modernize key elements of its CW program."
June 1999: A CIA report finds that Iran has sought "production technology, expertise, and chemicals that could be used as precursor agents in its chemical warfare (CW) program from entities in Russia and China."
October 2000: U.S. intelligence reports to Congress that Iran's chemical weapon stockpile includes "at least several thousand metric tons" of chemical agents.
December 2000: The CIA again reports that Iran possesses blister, blood, and choking agents, adding for the first time that its arsenal "probably" includes nerve agents.
June 2001: The United States imposes sanctions on a Chinese entity under the Iran Nonproliferation Act of 2000, reportedly for assisting in the construction of a facility in Iran which manufactures dual-use equipment that can be used to produce chemical weapons.
June 2001: The CIA reports that Iran is still seeking material and technological support from Russia and China for "its goal of having indigenous nerve agent production capability."
September 2001: Pars Company Inc. of Cary, North Carolina, pleads guilty to exporting two STX gas monitors from the United States to the United Arab Emirates and transshipping the monitors to Iran. The monitors are controlled for export by the U.S. Department of Commerce because of their possible use in the development or production of chemical and biological weapons.
May 2002: The United States imposes sanctions on two Armenian, eight Chinese, and two Moldovan entities under the Iran Nonproliferation Act of 2000 for transferring to Iran technology controlled under multilateral export control lists. Reportedly, four of these companies were sanctioned for providing chemical weapon materials.
2003: During the invasion of Iraq, U.S. forces discover Iraqi intelligence reports about Iran's use of chemical weapons during the Iran-Iraq War.
2003: The CIA reports that "Iran has not acknowledged the full extent of its chemical weapons program" and "is acting to retain and modernize key elements," including an offensive R&D program, an undeclared stockpile, and an offensive production capability.
April 2003: At the First Review Conference of the CWC, the United States accuses Iran of continuing "to seek chemicals, production technology, training, and expertise from abroad" for a chemical weapon program. The United States believes that Iran has stockpiled blister, blood, choking and perhaps nerve agents.
July 2003: The United States imposes sanctions on five Chinese and one North Korean entity under the Iran Nonproliferation Act of 2000 for transferring to Iran technology controlled under multilateral export control lists. Reportedly, some of the companies were sanctioned for selling chemicals and equipment that could be used in chemical weapons production.
October 2003: The head of the Iranian delegation to the Eighth Conference of States Parties to the CWC states that Iran has submitted all declarations and required information and criticizes the continued application of Australia Group export controls to CWC States Parties.
2005: Iran's military-controlled Imam Hossein University (IHU) and Malek Ashtar University (MUT) begin researching "chemical agents intended to incapacitate," according to U.S. intelligence.
August 2005: The U.S. Department of State's Bureau of Verification, Compliance, and Implementation "judges that Iran is in violation of its CWC obligations because Iran is acting to retain and modernize key elements of its CW infrastructure to include an offensive CW R&D capability and dispersed mobilization facilities."
December 2005: The United States sanctions two Indian companies under the Iran Nonproliferation Act of 2000, reportedly for the export of phosphorus oxychloride and trimethyl phosphite to Iran; both are Schedule 3 chemical weapon precursors, according to the CWC, and can be used in the production of nerve agents.
January 2006: According to The Guardian, an intelligence assessment drawing on material gathered by European governments claims that Iran has developed an extensive purchasing network for its biological and chemical weapon programs. Purchase requests and acquisitions are "registered almost daily," according to the assessment, and target suppliers in Western Europe and the former Soviet Union.
June 2006: The U.S. Treasury Department sanctions four Chinese companies and one U.S. company for having supplied missile-related and dual-use components to Iran's military for use in chemical weapon-capable missiles. The companies were designated under Executive Order 13382, an authority intended to financially isolate firms that proliferate weapons of mass destruction or missiles capable of delivering such weapons.
December 2006: The U.S. Director of National Intelligence reports that "Iran maintains a small, covert CW stockpile."
December 2007: The U.S. Director of National Intelligence reports that Iran "continues to seek production technology, training, and expertise from foreign entities" and that it "maintains a capability to weaponize CW agents in a variety of delivery systems."
July 2009: U.S. officials reportedly accuse the Chinese company Zibo Chemet of having supplied technology to manufacture glass-lined chemical reactor vessels to the Iranian firm Shimi Azarjaam.
July 2010: The U.S. Department of State's Bureau of Verification, Compliance, and Implementation reports that it "cannot certify whether Iran has met its chemical weapons production facility declaration obligations, destroyed its specialized CW equipment, or retained an undeclared CW stockpile."
November 2011: Revolutionary fighters reportedly find hundreds of artillery shells filled with mustard gas at two sites in central Libya. U.S. intelligence suspects that they are Iranian-origin.
December 2011: The U.S. Director of National Intelligence reports that Iran "continues to seek dual-use technologies that could advance its capability to produce CW agents" and "is capable of weaponizing CW agents in a variety of delivery systems."
2012: Iran begins marketing dibenzoxazepine (CR) gas as a riot control agent, according to U.S. intelligence.
July 2012: Iran reportedly has supported Syria's chemical weapons development, including by providing materials and expertise beginning as early as 2006.
2014: The Chemistry Department of Iran's Imam Hossein University seeks "kilogram quantities" of medetomidine, which it has researched as an incapacitant, from Chinese suppliers, according to U.S intelligence.
November 2018: The United States reportedly accuses Iran of failing to declare chemical weapon-related activities in violation of commitments to the CWC, citing Iran's ability to fill weapons with chemicals, the transfer of chemical-filled shells to Libya in the 1980s, and the marketing of dibenzoxazepine (CR) gas at defense exhibitions as a riot control agent.
January 2019: The U.S. Director of National Intelligence declares Iran in noncompliance with its CWC obligations, citing the development of "agents intended to incapacitate for offensive purposes" and Iran's failure to declare "all of its traditional CW agent capabilities when it ratified the CWC."
April 2019: The U.S. Department of State elaborates on alleged Iranian violations of the CWC, which include the transfer of chemical weapons to Libya during the 1978-1987 Libya-Chad War, the failure to declare its complete stockpile of Riot Control Agents (RCAs), and the failure to declare all CW production facilities. The report also cites "serious concerns" that Iran is currently developing offensive pharmaceutical-based agents.