In Broken Link Garak tried to nip the Dominion War in the bud, by incinerating the Great Link (after hearing from the Founder of her intent to exterminate all Cardassians) with the Defiant's quantum torpedoes, and Worf stopped him. If Sisko had not been around, Worf may not have had the opportunity. Of course, in that case Garak might not have been on board, either. Possibilities are open.