“Friendly” is the military’s word for one’s own side, as in “friendly forces.” Attach it to “fire” and you get a phrase that describes the worst thing that can happen in a unit, shooting your own people, with an adjective usually reserved for dogs and waiters.

The euphemism works on two levels. It reclassifies the dead: they were not killed by the enemy, so the tally goes in a different column. And it reclassifies the act: “fire” happens, the way rain happens, and its friendliness is a property of its source rather than a judgment on its result.

Mamet writes that nothing good comes of language used inappropriately. The specific harm here is institutional. A force that calls this “friendly fire” has a vocabulary for not examining it too closely, and a force that does not examine it will do it again.