The use of chemical weapons as a method of warfare can be traced back to the earliest dates of human history. However, modern historians accept that chemical substances have been used as weapons of mass destruction (WMDs) since the early twentieth century. Although the first convention which banned the use of chemicals as a tool of warfare was the Strasbourg Agreement in 1675, chemical weapons (CWs) were used on a mass scale in the First World War and repeatedly thereafter. The Iran-Iraq war in the 1980s was an experiment in the use of CWs and it was during this war that CWs started to be used as conventional weapons of war. In this study, examples of chemical attacks during the Iran-Iraq War are discussed. The development of CWs such as the armaments deployed in the Middle East cannot be isolated from international politics, and should therefore not be studied without taking the major world powers into consideration. Therefore, attitudes of the US, the UK, France, Israel, Germany, Italy, and Russia, none of which were participants in this war, are also to be examined. In order to create the chronological and informational groundwork of this study, a literature review was conducted and printed works were used. US national intelligence reports and diplomatic correspondence were examined. The media during the period, statements by politicians, United Nations Security Council reports, and the memories of witnesses exposed to chemical attacks during the war are included to advance the study.