Iran Air 655 was squawking correctly and following its normal commercial air transport route.
The Vincennes should never have been where it was; it was commanded by a gung-ho 'shoot first' captain eager for combat who didn't actually follow the correct RoE.
One of the most disgraceful acts of US aggression ever. The original inquiry was a total whitewash, but the Navy's attempts to cover up the truth were eventually revealed.....