There are some who say this is the greatest episode of Star Trek ever made. I will not argue that fact.
Two words: Elim Fucking Garak. He’s one of the most fascinating characters ever to grace a television screen. And he’s allowed to totally dominate this episode and Sisko’s sense of morals.
He and Sisko cook up a Gulf of Tonkin operation in order to bring the Romulans into the Dominion War. It works, though not the way Sisko intended. But if you aren’t willing to go all the way, don’t bother the Cardassian tailor.