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.
November 1983: In a communication to the United Nations, Iran alleges that it has been targeted with chemical weapons by Iraq.
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 D.I.A. believes that the program began under the auspices of the Islamic Revolutionary Guard Corps, with some assistance from the Ministry of Defense.
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.
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.
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.
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.
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.
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 technologyâ€¦ [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.
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.
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 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 C.I.A. 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 Central Intelligence Agency 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.
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.
November 1997: Iran ratifies the Chemical Weapons Convention.
May 1998: At the Third Conference of States Parties to the Chemical Weapons Convention, 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 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.
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.
April 2003: At the First Review Conference of the Chemical Weapons Convention, 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 Chemical Weapons Convention states that Iran has submitted all declarations and information required by the CWC and criticizes the continued application of Australia Group export controls to CWC States Parties.
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 precursors, according to the Chemical Weapons Convention, 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.
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.
March 2010: The Office of the Director of National Intelligence reports that “Iran is capable of weaponizing CW agents in a variety of delivery systems,” that “Iran maintains the capability to produce chemical warfare (CW) agents,” and that Iran “continues to seek dual-use technologies that could advance its capability to produce CW agents.”