A single passage from a New York Times book review:

Among such “slights,” of course, none loom larger than America’s, not least the C.I.A.-backed 1953 coup that overthrew Prime Minister Mohammed Mossadegh and the mistaken 1988 shooting-down of Iran Air Flight 655, in which 290 people perished.

If Iran had shot down an American passenger jet in U.S. airspace, this would read:

...and the 1988 terrorist attack on American Airlines Flight 655, in which 290 people were killed.

But it's only terrorism when they do it. By definition.

Notice also how Iranian victims of U.S. terror aren't "killed" or "murdered". They simply "perish", like crops too long in the sun.