A conflict fought in 2373, at station Deep Space Nine in the Bajoran Sector. The Second Battle of Deep Space 9 was the first engagement of the Dominion War, and officially commenced hostilities. A Dominion fleet, including warships from the Cardassian Union, and led by Gul Skrain Dukat, launched an assault on the Federation-held starbase Deep Space 9. Although the station was captured by Dominion forces, the battle was a strategic triumph for the Federation, which successfully mined the Bajoran wormhole. This prevented the Dominion sending reinforcements from the Gamma Quadrant, denying them a swift and decisive victory in the coming struggle.

Following their annexation of the Cardassian Union around stardate 50560, the Dominion began fortifying their foothold in the Alpha Quadrant. Weekly convoys of warships and troops were sent through the Bajoran wormhole, travelling on to Cardassian space. Within a few months, Cardassia became a veritable fortress, teeming with Jem’Hadar soldiers and their Vorta overseers. Although a technical state of war with the United Federation of Planets didn’t exist, and neither side had fully committed to immediate combat, numerous skirmishes took place along the former Demilitarized Zone. Aside from the Dominion’s attempt to destroy the Bajoran System with a trilithium bomb, the Jem’Hadar and Cardassians attacked and destroyed numerous Federation and Klingon patrol ships, in a sustained campaign across the border sectors.

In addition to military advances, the Dominion made major inroads into the Alpha Quadrant politically, signing nonaggression pacts with several regional powers, including the Miradorn and the Tholian Assembly. They later offered similar pacts to Bajor and other independent worlds in the area. The Dominion’s greatest diplomatic achievement, though, was the signing of a nonaggression pact with the Romulan Star Empire, the third major power in the region. The Dominion’s goal seemed clear: to isolate the Federation politically and militarily. Its classic strategy of divide-and-conquer seemed to be succeeding admirably; aside from the Klingon Empire, the Federation stood virtually alone in opposing the new Cardassian government. With peaceful means failing to slow Dominion advances, Deep Space 9 Captain Benjamin Sisko observed, “a war may be our only hope”.

With its strategic advantage rapidly eroding, the Federation resolved to prevent the Dominion from sending further reinforcements into the Alpha Quadrant. President Min Zife gave approval to a plan outlined by Sisko; his warship, the Defiant NX-74205, would mine the entrance to the Bajoran wormhole. Maintenance engineer Rom suggested using self-replicating mines equipped with cloaking devices for the blockade; not only would such a minefield be undetectable to approaching ships, it would also be virtually indestructible. Each mine destroyed would be replaced by other, newly replicated mines in the vicinity. Officers Miles O’Brien and Jadzia Dax quickly developed a working model, and the Defiant immediately began laying the minefield.

This action could be seen as nothing less than a provocation for war, and the Dominion’s primary overseer on Cardassia, Weyoun, demanded that the mining be halted immediately. Captain Sisko flatly refused. An intricate dance of lies and intimations began: Weyoun claimed the Cardassians, having suffered terrible damage during the Klingon-Cardassian War, required a great deal of assistance in rebuilding their infrastructure and defending against renewed Klingon invasion. Sisko played along, claiming he had no idea the Cardassians’ situation was that bad. The two representatives arranged a deal, in which the Federation would remove the minefield, and the Dominion would restrict further convoys to non-military personnel and material. However, both sides were merely using this repartee as a ruse to buy time - Weyoun to prepare the Dominion fleet for attack, and Sisko to complete the minefield. With war imminent, Sisko, acting in his role as Emissary, requested that the Bajoran Provisional Government sign the non-aggression pact offered them by the Dominion, ensuring the planet and its people would be kept out of the now-inevitable conflict.

Intent on preventing its lifeline to the Gamma Quadrant from being cut, the Dominion launched a massive assault fleet towards Deep Space 9, with Skrain Dukat himself in command. For reasons then unknown, the Federation had not reinforced its position at Deep Space 9, leaving only Defiant and the IKS Rotarran to supplement the station’s defences. Anticipating the enemy attack, Captain Sisko ordered Rotarran to patrol the border, and provide advance warning when the fleet approached. The incoming assault force arrived quickly, comprised of nearly 300 Jem’Hadar and Cardassian warships.

Sisko refused Dukat’s suggestion that he surrender, and both sides prepared for the onslaught. As the Dominion fleet opened fire, Weyoun and Dukat were unpleasantly surprised to find Deep Space Nine’s shields holding. Federation deflectors had previously been impotent at defending against the Jem’Hadar’s phased polaron beam weaponry, but upgrades has since taken place. Dukat ordered more ships to open fire on the station. Meanwhile, the Defiant herself was coming under attack as she desperately worked to complete the minefield. Rotarran provided interference and covering fire, giving the Defiant enough time to finish the task. The minefield was activated, sealing the wormhole to traffic. Despite this victory, Deep Space Nine was by now in trouble. Using his knowledge as the outpost’s former commander, Dukat was able to cut main power to the shields. Heavy bombardment soon crippled the station.

With the wormhole blocked, and the station now essentially impossible to hold, Sisko ordered all Starfleet personnel to evacuate. As Dukat ordered his reserve units into battle, the station’s crew boarded the Defiant and Rotarran, taking all sensitive equipment with them, and leaving the station in the hands of the Bajoran Militia. As the evacuation neared completion, Sisko addressed the remaining station residents on the Promenade, promising, “I will not rest until I stand with you again, here”. Once the Defiant and Rotarran had safely departed the station, Bajoran Major Kira Nerys activated Program Sisko 197, which sabotaged almost all the station’s computer and power systems, leaving it a near-lifeless hulk. Dominion and Cardassian troops subsequently boarded the station, officially reclaiming “Terok Nor”.

Ultimately, the battle was nothing but a pyrrhic victory for the attackers, because the minefield operated independently from the station, and proved resistant to all initial attempts to dismantle it. Likewise, the sabotage of the station itself meant it served little function other than that of a command and supply post behind the front lines. In addition, while the Dominion had thrown its full force towards capturing the station, a combined Starfleet-Klingon taskforce had crossed the border into Cardassian territory, destroying the shipyards at Torros III, nearly unopposed. This victory would have much greater impact in the short- and mid-term course of the war, as the Dominion’s shipbuilding capabilities were seriously affected by the loss of that facility. Ultimately, Deep Space Nine would be recaptured by a joint Starfleet and Klingon assault in the Battle of Bajor , AKA Operation Return, approximately five months later.