United Nations Security Council Resolution 612 was adopted on May 9, 1988, after considering a report by the Special Mission dispatched by the Secretary-General to investigate the alleged chemical warfare that had been occurring in the Iran–Iraq War.

With the outbreak of the Iran-Iraq War, and despite the international ban on the use of chemical weapons in warfare, Iraq repeatedly used such weapons in its attacks on Iran, causing the martyrdom or injury of more than 100,000 Iranian military personnel and civilians.⁠[1]

As Iraq’s chemical attacks continued in the early years of the war, Iran distributed color booklets in Western Europe in November 1983 showing images of chemical weapons victims in Tehran hospitals. Despite Iran’s efforts to draw public attention to Iraq’s chemical assaults, these actions did not create much reaction in the West. Therefore, in early 1984, Iran sent at least fifty chemical‑warfare casualties to hospitals in the United Kingdom, Belgium, Austria, Switzerland, and Sweden for treatment in order to show the consequences of Iraq’s attacks. Even with clear evidence that Iraq had used chemical weapons against Iran and despite extensive efforts to expose this crime, international organizations were unwilling to respond, a situation that emboldened Saddam and other senior Iraqi decision-makers to expand the use of chemical weapons.⁠[2]

Throughout the war years, Iran’s diplomatic efforts to condemn Iraq’s use of such weapons yielded no tangible results.

On March 1, 1984, the United Nations examined Iran’s claims, and the UN Secretary-General, Javier Pérez de Cuéllar, sent a team of experts from Australia, Spain, Sweden, and Switzerland to the region. They spent six days in Iran inspecting and collecting samples in areas such as Ahvaz, where chemical weapons had been used. After completing its work, the team submitted a joint report to the Security Council. Presented on March 26, 1984, the report stated that chemical weapons had been used in the inspected areas in the form of aerial bombs and that the agents employed included mustard gas and the nerve agent tabun.⁠[3]

Following the publication of this report, the United Kingdom, the United States, France, and Japan banned the sale to Iraq of any precursor materials used in producing mustard gas and nerve agents. Australia later joined these sanctions.⁠[4]

Nonetheless, Iraq continued to use various types of chemical weapons on a large scale in operations such as Badr (1985), Valfajr 8 (1986), Karbala 6 (1987), and Nasr 4 (1987).⁠[5] The peak of Iraq’s chemical weapons use came on March 15, 1988. On that day, while the Islamic Revolutionary Guard Corps (IRGC) units were carrying out the third phase of Operation Valfajr 10 in the Halabja region inside Iraqi territory, Iraq—unable to confront the advancing forces and with many of its troops encircled—bombarded Halabja and its surrounding areas with chemical weapons. This attack caused the martyrdom and injury of tens of thousands of civilians.⁠[6]

Four days after the Halabja bombing, the first group of foreign journalists arrived in the area at the invitation of the Islamic Republic of Iran. From March 21, 1988, Iranian officials also launched a wide-ranging campaign to draw global attention to the major humanitarian disaster whose full dimensions were still unknown. Correspondence with officials in other countries and sending footage of the Halabja chemical bombing helped publicize the tragedy. In the meantime, Iran called for international assistance to treat the chemical casualties.⁠[7]

On the 17th of March 1988, Iran’s Deputy Permanent Representative to the UN wrote to the Secretary-General, referring to Iraq’s large-scale chemical attacks on Halabja and calling on the organization to pressure Iraq to end its continued use of chemical weapons; failing that, Iran warned it might resort to retaliatory measures.⁠[8]

On March 21, 1988, Iran also requested that the Secretary-General dispatch a team of chemical weapons experts to the region to investigate Iraq’s crimes and report to the international community.⁠[9]

Alongside these diplomatic efforts, Iran reported on the dire condition of victims of Iraq’s chemical attacks,⁠[10] declared public mourning,⁠[11] and maintained extensive correspondence with the UN,⁠[12] developments that led some countries to align more closely with Iran. Japan⁠[13] and Argentina,⁠[14] for example, sent letters to the UN Secretary-General condemning Iraq’s chemical attacks.

On April 5, 1988, Iran’s Foreign Minister wrote to the UN Secretary‑General, criticizing what he described as the organization’s biased actions and, while referring to the findings of the investigative mission, argued that the Secretary‑General’s conclusions should result in a binding decision prohibiting the use of chemical weapons—one that both parties would be obliged to observe.⁠[15]

On April 25, the mission sent to the Iran-Iraq War zones confirmed in a detailed report that Iraq had used chemical weapons.⁠[16] Subsequently, on May 6, the Federal Republic of Germany, Italy, and Japan submitted a draft of Resolution 612 to the Security Council, which was unanimously adopted at the Council’s session on May 9, 1988:

“The Security Council,
Having considered the report of April 25, 1988, (S/19823) 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;
Dismayed by the mission’s conclusions that chemical weapons continue to be used in the conflict and that their use has been on an even more intensive scale than before;
l. Affirms the urgent necessity of strict observance of the Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare, signed at Geneva on June 17, 1925;
2. Condemns vigorously the continued use of chemical weapons in the conflict between the Islamic Republic of Iran and Iraq, contrary to the obligations under the Geneva Protocol;
3. Expects both sides to refrain from the future use of chemical weapons in accordance with their obligations under the Geneva Protocol;
4. Calls upon all States to continue to apply or to establish strict control of the export to the parties to the conflict of chemical products serving for the production of chemical weapons;
5. Decides to remain seized of the matter and expresses its determination to review the implementation of the present resolution”.⁠[17]
An important and positive aspect of this resolution was that, for the first time, the Security Council examined the issue of chemical‑weapons use entirely independently of the broader question of the war and addressed it separately from other matters—an approach regarded as a significant diplomatic achievement for the Islamic Republic of Iran.⁠[18]

Iraq’s disregard for the provisions of Resolution 612 and its continued use of chemical weapons against Iran led the Security Council, a few months later, to adopt a more explicit resolution against Iraq and, for the first time, to recognize it as the party that had used chemical weapons.