US involvement with Iraqi use of gas in Iran-Iraq War

Wikipedia:

Declassified CIA documents show that the United States was providing reconnaissance intelligence to Iraq around 1987–88 which was then used to launch chemical weapon attacks on Iranian troops and that the CIA fully knew that chemical weapons would be deployed and sarin and cyclosarin attacks followed.^[209]

On 21 March 1986, the United Nations Security Council made a declaration stating that „members are profoundly concerned by the unanimous conclusion of the specialists that chemical weapons on many occasions have been used by Iraqi forces against Iranian troops, and the members of the Council strongly condemn this continued use of chemical weapons in clear violation of the Geneva Protocol of 1925, which prohibits the use in war of chemical weapons.“ The United States was the only member who voted against the issuance of this statement.^{[210][note 4]} A mission to the region in 1988 found evidence of the use of chemical weapons, and was condemned in Security Council Resolution 612.

According to Walter Lang, senior defense intelligence officer at the U.S. Defense Intelligence Agency, „the use of gas on the battlefield by the Iraqis was not a matter of deep strategic concern“ to Reagan and his aides, because they „were desperate to make sure that Iraq did not lose“. He claimed that the Defense Intelligence Agency „would have never accepted the use of chemical weapons against civilians, but the use against military objectives was seen as inevitable in the Iraqi struggle for survival“.^[148] The Reagan administration did not stop aiding Iraq after receiving reports of the use of poison gas on Kurdish civilians.^[211][212]