The attack occurred during the Iran-Iraq war, which had begun in 1980 with Saddam Hussein’s invasion of Iran. The US government backed Saddam, and sent warships to the Persian Gulf to support the Iraqi war effort.
One of those warships was the USS Vincennes which, on 3 July 1988, fired two missiles at Iran Air Flight 655 while it was making a routine trip to Dubai.
Washington claimed the US Navy had acted in self-defence, but this wasn’t true. The plane had not, as the Pentagon claimed, moved “outside the prescribed commercial air route”, nor had it been “descending” towards USS Vincennes at “high speed”.
The US thus shot down a civilian airliner, and haphazardly tried to cover it up. Some 66 children were among the 290 civilians killed.