collateral damage; getting caught up in another's trouble
Idiomatic expression derived from a classical Chinese story; used when an innocent party suffers harm due to a dispute or disaster that is not their own. Often carries a literary or formal tone.
Because of the war in the neighboring country, our own nation also suffered collateral economic damage.
He got caught up in the fight between his bosses; it was truly a case of collateral damage.
From a classical Chinese anecdote where a fire in a city gate spread to a nearby pond, killing the fish. The expression metaphorically refers to innocent bystanders suffering from a disaster they did not cause.