In July 1988 , Iraqi aircraft dropped bombs on the Iranian Kurdish village of Zardan . Dozens of villages , such as Sardasht , and some larger towns , such as Marivan , Baneh and Saqqez , were once again attacked with poison gas , resulting in even heavier civilian casualties . About the same time , the USS '' Vincennes '' shot down Iran Air Flight 655 , killing 290 passengers and crew . The lack of international sympathy disturbed the Iranian leadership , and they came to the conclusion that the United States was on the verge of waging a full-scale war against them , and that Iraq was on the verge of unleashing its entire chemical arsenal upon their cities
Iran Air Flight 655
Iran Air Flight 655
Iran–Iraq War