Fury and frustration still mount over the downing of Malaysia Airlines Flight 17, and justly so. But before accusing Russian President Vladimir Putin of war crimes or dismissing the entire episode as a tragic fluke, it's worth looking back at another doomed passenger plane—Iran Air Flight 655—shot down on July 3, 1988, not by some scruffy rebel on contested soil but by a U.S. Navy captain in command of an Aegis-class cruiser called the Vincennes.

A quarter-century later, the Vincennes is almost completely forgotten, but it still ranks as the world's seventh deadliest air disaster (Malaysia Airlines Flight 17 is the sixth) and one of the Pentagon's most inexcusable disgraces.