Following the end of the Dominion War in the Alpha Quadrant. A majority of the Dominion returned to the Gamma Quadrant to find general upheaval and unrest. The once thought Gods, the Founders, were seen as mortals by the many worlds subjugated by the Dominionn.
Without fear, several worlds rebelled and began constant bombardment and resistance against the Jem'Hadar. One of the more successful worlds, NauVallus Prima actually launched sneak attacks on dozens of Jem'Hadar ship yards effectively crippling their ability to hold the Gamma Quadrant.
When Odo returned to the Great Link, he forbade any retribution on the NauValla as their actions were merely an act of independence and recriprocity for the Dominions many acts of cruelty to many species.
The NauValla Hornet Ship possessed long range teleportation and phasing torpedoes which did heavy damage to the Dominion fleets. Earlier incursions had been met with viral bombardments of their world, which resulted in billions dead. The rebellion against the Dominion was more than justified to the Nauvalla.
Eventually a cease fire was agreed to, but the NauValla sealed their borders and mined the surrounding space with cloaked self replicating mines (as inspired by the Federation).