...Although if we wanted, we could still claim that it was. That is, a ship leaving Earth 200 years ago might have spent 180 years at sublight (or low warp), with the colonists in cryosleep as was customary for the time (Harry Kim describes a cryosleep colonizer from as late as 2210). They would awake at their promised land - only to meet a Starfleet vessel whose captain would tell them that it would be a really
bad idea to set shop down there because the Cardassians were right next door, but that as UFP citizens, they had the right to do so nevertheless.
His actions definitely slowed down Cardassian efforts to fortify their border with the Federation and their ability to launch an offensive strike.
How so? He destroyed two warships and one transport that may or may not have been contributing to the escalation effort. Hardly a devastating loss, considering what we later learn of the scale of the Cardassian military. And nothing in his actions was indicated to have the consequence of discouraging the Cardassians; to the contrary, at the conclusion, the villains of the week learned that Starfleet would not
inspect their shipments.