Iraqi chemical weapons program

The Iraqi chemical weapons program was an aspect of the country's pursuit of weapons of mass destruction until the 1990s. In violation of the Geneva Protocol, Iraq initiated three separate research and development drives for chemical weapons, the first two of which (1970–1974; 1974–1978) were unsuccessful. The last drive (1978–1991), which was spurred by Iraqi president Saddam Hussein, was successful and saw the deployment of chemical weapons during the country's military campaigns against Iran and the Kurdish people.

Efforts by Iraq to acquire chemical weapons date back to the early 1960s and were motivated by a desire to greatly strengthen the Iraqi military, especially after the 1973 Arab–Israeli War. However, it was not until Hussein's regime that the program experienced significant and steady progress. Though lacking stockpiles at the time of the Iraqi invasion of Iran in 1980, the country rapidly engaged in intensive research to produce and store chemical weapons, with real-time battlefield deployments serving as tests for the prowess of Iraqi forces in waging chemical warfare.

Beginning in 1983, Iraqi chemical attacks against Iran were confirmed by the United Nations to have taken place on multiple occasions over the course of the Iran–Iraq War, including more than 30 targeted attacks against Iranian civilians. It is estimated that these chemical attacks resulted in over 100,000 Iranian casualties, of which at least 20,000 were direct deaths upon exposure. The Iraqi military also used chemical weapons against Kurdish civilians during the 1988 Anfal campaign (as evidenced by the Halabja massacre), which resulted in the deaths of as many as 100,000 people, according to Human Rights Watch. In January 1991, during the Iraqi occupation of Kuwait, Iraq began firing missiles at civilian targets in Israel and at American troops in Saudi Arabia, raising concerns of potential chemical attacks, but all of the warheads used were conventional. However, chemical weapons were reportedly deployed again during the 1991 Iraqi uprisings.

According to Iraqi government sources, while the majority of its mustard gas was of 90–95% purity, it struggled to consistently produce nerve agents of high purity. The average purity of its tabun was 50–60%, but production was abandoned in 1986 in favour of concentrating on sarin. The average quality of sarin and related products was in the range of 45–60%, which was sufficient for immediate deployment against the Iranians, but not for long-term storage. The development of VX after 1988 was relatively unsuccessful, with the achieved purity of 18–41% considered insufficient for weaponization. The highly secretive Iraqi biological weapons program, which was discovered by the United Nations Special Commission during the Iraq disarmament crisis, pursued a similar course: Iraq had deployed biological warheads (containing anthrax and botulinum toxin) to attack the Gulf War coalition at various locations, but Hussein reportedly decided against using them. Continued concerns over Iraqi weapons of mass destruction contributed to the 2003 invasion of Iraq, though it was later discovered that Iraq had destroyed its stockpile in the 1990s.