User blog comment:Hawki/Nova Covert Ops, part 3 - Reflections/@comment-250398-20161201052518/@comment-72.197.211.140-20161201062118

Again Hawki, in the case with Vardona, you don't really know that. The main problem here is we don't know how much Dominion intel knows about the Tal'darim. Besides the whole point of Davis's rebellion, from the public POV, was to show them the zerg are still a threat. At the end of the Tyrador IX mission, Kate was talking about the return of the Protoss, and did state that no one knew of they came merely to kill the zerg, or terrans too. The point is that the Dominion people didn't know what the Protoss were up to this time. Last time, given the events of SC1, they burned terran worlds, but their goal was only to kill the swarm, not go outright killing the terrans for the hell of it. It's possible that the people of Vardona felt since there aren't any feral zerg on the planet, the Protoss wouldn't come to glass this world. If that's the case, there's no real need to put military defenses like that to prevent purification.