Dominion War The Dominion War was a major interstellar conflict , fought from 2373 to 2375 , though related conflicts began earlier . The war involved all major powers of the Alpha and Gamma Quadrant s , organized into two opposing military alliances : the Federation Alliance and the Breen - Dominion Alliance . Marked by massive military and civilian casualties , including the systematic destruction of the Cardassian population ( in which more than eight hundred million Cardassians were killed ) , and the mobilization of starship fleet s on a massive scale , it was one of the bloodiest and most destructive wars in modern galactic history . Prelude . Following initial Alpha Quadrant expeditions into the Gamma Quadrant , rumors began to filter through of a ruthless race of conquerors known only as " The Dominion " . In 2370 , first contact was officially made between the Federation and the Dominion , when the Jem ' Hadar destroyed the Starfleet vessel . A state of cold war rapidly developed thereafter between several of the Alpha Quadrant ' s major powers and the Dominion . A Dominion invasion was widely regarded as inevitable , as the Founder s were driven by a xenophobic need to exert absolute authority over all other civilizations . ( ) The Dominion began to infiltrate the Alpha Quadrant with Changeling s masquerading as important officials , in an attempt to destabilize the political landscape between the major powers . By manipulating a plan originating with Enabran Tain , the Dominion destroyed the Obsidian Order and nearly crippled the Tal Shiar at the Battle of the Omarion Nebula in 2371 . The subsequent power vacuum left in the absence of the Obsidian Order led to a " coup " on Cardassia , resulting in the overthrow of the Cardassian Central Command by the Detapa Council . By manipulating frustrated warrior sentiments in the Klingon Empire , and implanting false information that the Cardassian change of government had been engineered by the Founders , the Dominion was able to trigger the Klingon - Cardassian War . The Federation condemned the Klingon invasion , leading to a severe deterioration of relations between the two powers , ultimately concluding with the . Concurrently , the Dominion was almost able to instigate a war between the Federation and the Tzenkethi , and caused mass hysteria on Earth following the bombing of the Antwerp Conference in 2372 , which in turn led to a failed " coup " attempt of Starfleet personnel under Admiral Leyton . ( ) As part of a preemptive defensive effort , the Trill government cooperated with Starfleet in trying to seal the wormhole permanently in 2373 , without damaging the beings living within . The attempt was sabotaged by a Changeling infiltrator disguised as Julian Bashir . The Bashir Changeling was stopped by the crew of the in his attempt to destroy the Bajoran sun and thus killing all life in the system as well as destroying the Federation , Klingon , and Romulan fleet s that were at Deep Space 9 at the time . ( ) The Klingon invasion of Cardassia had all but destroyed Cardassian infrastructure . In mid - 2373 , frustrated at the apparent cowardice of the Detapa Council , and the broken state of the Cardassian people , Gul Dukat negotiated the entry of the Cardassian Union into the Dominion . Dukat himself was placed as head of the new Cardassian government . The Dominion rapidly began fortifying Cardassia with heavily armed convoy s on a weekly basis . Within three days of their arrival , the Jem ' Hadar had expelled the Klingons from Cardassian space entirely , and completely annihilated the Maquis in the Demilitarized Zone . In the face of the new Dominion foothold in the Alpha Quadrant , the Federation and the Klingons renewed the Khitomer Accords . ( ) Although open war did not begin immediately , violence along the Cardassian border escalated , with ships such as the and the being reported missing , though both were later located . The Dominion began making strategic political inroads in the Alpha Quadrant , signing nonaggression pact s with the Tholian Assembly , the Miradorn , Bajor , and , perhaps most significantly , the Romulan Star Empire . With five large convoys having entered the Alpha Quadrant unopposed , the Federation Alliance realized they would soon face an impossible strategic position . In late 2373 , the Federation thus decided to mine the entrance to the Bajoran wormhole with self - replicating mine s in a last - ditch effort to permanently stop the flow of Dominion reinforcements into the Alpha Quadrant . Both sides knew that this act would lead to open war . ( ) Open war begins . " " We ' re losing the peace , which means a war could be our only hope . " " Intent on preventing the Federation from completing the minefield , Weyoun arrived on Deep Space 9 and delivered an ultimatum ; either Sisko would remove the mines , or the Dominion would . Sisko refused the ultimatum , and , two days later , a large Dominion fleet attacked and captured Deep Space 9 . Trusting that the minefield would be activated in time , the Federation Alliance opted not to reinforce the station , but used the opportunity to take advantage of the diverted Dominion ships to destroy the Dominion shipyards at Torros III . Though the minefield was successfully activated , the Allies were forced to retreat from the Bajoran system , and the station was subsequently garrisoned by Dominion forces . ( ) Over the following months , Allied forces were forced to retreat on all fronts in the wake of several decisively successful Dominion campaigns . At each instance , the Allies suffered catastrophic losses . During this campaign , Starfleet suffered one of its worst defeats of the war when the Seventh Fleet was dispatched to halt the Dominion ' s advance at the Tyra system . In the subsequent battle , 98 starships were destroyed out of a fleet of 112 , leaving thousands dead . Morale among the forces of the Federation Alliance plummeted , and it became a question of when , not if , the Alliance would be defeated . ( ) While the Allies suffered repeated defeats in large fleet actions , Starfleet and Klingon ships had greater success in raiding operations and in combating small patrols of Jem ' Hadar ships . Such operations included the destruction of the Dominion ' s primary ketracel - white storage facility in the Alpha Quadrant , and the destruction of a massive Dominion sensor array in the Argolis Cluster . The Dominion began suffering a shortage of ketracel - white , greatly concerning the Cardassians in particular . Glinn Damar even proposed that the last rations of white be poisoned if new supplies could not be secured , preventing the Jem ' Hadar from running amok . Nevertheless , the Dominion continued to conquer large swathes of Federation and Klingon territory , even approaching the Vulcan border and Bolian territory . On Deep Space 9 , efforts to dismantle the minefield surrounding the wormhole were finally beginning to bear fruit . Although Allied forces scored several minor successes in single - ship duels and in small groups , the inexorable Dominion advance compelled them to continually retreat . Morale sunk lower , with even the Klingons doubting they could defeat the Dominion . ( ) Counter - offensive . " " Earth isn ' t the key to the Alpha Quadrant , the wormhole is , and , whoever controls Deep Space 9 , controls the wormhole . " " By the latter half of 2374 , the Allies were perilously close to defeat . A major victory was needed , if anything to boost morale . Captain Benjamin Sisko , knowing the Dominion would likely figure out how to disable the minefield eventually , proposed to Starfleet Command the Federation Alliance had to go on the offensive . Sisko ' s plan was to assemble a task force to recapture Deep Space 9 , the most strategically important site in the Alpha Quadrant , at the mouth of the wormhole . Despite misgivings that it would leave Earth vulnerable , Starfleet approved the plan . The Klingons proved more difficult to convince ; Chancellor Gowron held the same concerns as Starfleet , in committing as many ships as would be required to re - take Deep Space 9 , it would leave the Empire vulnerable . While General Martok and Lieutenant Commander Worf made Starfleet ' s plea to Gowron in person , Federation forces began assembling at Starbase 375 . Unfortunately , Starfleet soon received intelligence from active resistance members on Deep Space 9 that the minefield was only three days from being destroyed . With no word having arrived from the Klingons , and only two - thirds of the Starfleet force assembled , Vice Admiral William Ross authorized Benjamin Sisko to lead the 627 ships assembled in an effort to prevent the Dominion from removing the mines . In response , Dukat pulled 1 , 254 warships from the front lines to intercept the Federation fleet , stalling Dominion advances into Allied territory . ( ) Though outnumbered two to one , Starfleet engaged the Dominion fleet . With the timely arrival of Klingon forces , the Dominion lines collapsed , and the fleet dispersed . Though the breached the lines , it was unable to prevent the destruction of the minefield . With no options remaining , Sisko took the " Defiant " into the wormhole , and was able to strike a bargain with the Prophet s to remove the Dominion forces to protect Bajor . 2 , 800 Dominion ships were destroyed in the wormhole , and with two hundred Allied ships approaching Bajor , the Dominion position on Deep Space 9 became untenable . The Dominion withdrew all forces to Cardassian territory , giving the Allied forces a decisive victory . Dukat suffered a mental breakdown at the defeat , along with the concurrent murder of his daughter , Tora Ziyal , and was captured by the victorious Allied forces . Damar was subsequently promoted to legate , and succeeded him as leader of the Cardassian Union . ( ) Lull . Following the decisive Allied victory in recapturing Deep Space 9 , the Dominion forces withdrew to Cardassian space , and major operations temporarily ceased . ( ) Legate Damar extended an olive branch to the Federation , hoping to negotiate a cease fire and end the war . Weyoun proposed to redraw the Federation - Cardassian border to give disputed star systems to the side with " de facto " control , an arrangement which generally favored the Federation . However , a think - tank of genetically engineered individuals led by Julian Bashir deduced that the Dominion ' s true goal was to obtain the Kabrel system . Though strategically unimportant , the Kabrel system would enable the Dominion to produce near - endless amounts of ketracel - white . Bashir advised that the Federation accept the peace proposal ; while many suspected the Dominion would renege on any agreement to buy time to re - group , the Allies were in a far greater need of a respite than the Dominion . Instead , the Federation made a counter - proposal and the talks ended inconclusively . ( ) Several weeks later , Dominion activity began to increase all along the border , putting to rest hopes that the Allied recapture of Deep Space 9 would signal the end of the war . Allied losses began to mount , including the destruction of the and the . ( ) In an effort to weaken the Federation - Klingon alliance , Dominion agents established ties with the Orion Syndicate in an unsuccessful plot to assassinate a Klingon diplomat opposed to the war and frame the war proponents led by Gowron for it . ( ) With the Prophets barring passage of the wormhole to ships from the Gamma Quadrant , the Dominion began breeding legions of Jem ' Hadar , tailoring their genetic profiles for combat in the Alpha Quadrant , and pushed their shipyard s to full construction capacity . ( ) The issue of a possible ketracel - white shortage became less imminent when the Dominion acquired new supplies of the drug manufactured by the Son ' a . ( ; ) Having recovered from the loss of Deep Space 9 , in late 2374 , the Dominion launched a surprise invasion of Betazed from the Kalandra sector , capturing the planet in less than ten hours . With control of this key Federation member world , the Dominion had scored a decisive strategic success ; it was now in a position to launch offensives against , Andor , Tellar , and Alpha Centauri . The Second Fleet launched three counter - attacks in just one month against Betazed ; however all were repulsed . For the Federation Alliance , suffering from shortages of ships and manpower , defeat once again seemed only a matter of time . ( ) The Tide Turns . " " Think about it , they ' re in the perfect position . They get to sit back and watch as their biggest rivals slug it out in a long , bloody war . No one ' s threatening their interests . Why should they risk their necks ? There ' s simply no reason for them to get involved in " our " war . " " The Romulan Star Empire had hitherto remained neutral in the Dominion War , although they were turning a blind eye to Dominion warships crossing through their territory to ambush Federation convoys and shipping . Captain Benjamin Sisko reasoned that the addition of the Romulan military could prove decisive in reversing the fortunes of the Dominion . With the help of Elim Garak , and the approval of Starfleet , a covert mission was carried out to implicate the Dominion in a planned invasion of Romulus ; however , Garak used this operation for the assassination of Senator Vreenak , the most ardent pro - Dominion advocate in the Romulan Senate . From the wreckage of Vreenak ' s destroyed ship , the Tal Shiar recovered a recording of an alleged top - level Dominion conference bringing forward the planning of the invasion . In response , the Romulan Empire officially declared war on the Dominion . Within hours , the Romulans struck fifteen bases along the Romulan - Cardassian border , opening the Romulan front to the war . Although progress remained slow for the allies , the Romulans drove Dominion forces off of Benzar within months of joining the war effort . During the Romulan fight against the Dominion , Shinzon distinguished himself in the Romulan military , leading twelve major engagements against the Jem ' Hadar , all of them successful . ( ; ) The Federation , desperate for additional support , continued to extend diplomatic ties to neighboring species . In 2374 , the Federation Council conveyed an official diplomatic message to Grand Nagus Zek of the Ferengi Alliance , which Jake Sisko speculated was a proposal for an alliance . In 2375 , the Federation accepted the Evora as a protectorate , despite their having achieved warp drive only the previous year . ( ; ) With the Romulans now fully committed to the Federation Alliance , options for a general offensive into Cardassian territory became a viable possibility . The Romulans had reservations that such an attack could succeed only at horrendous cost , favoring to contain the Dominion within Cardassian space . However , Benjamin Sisko convinced their delegation that the only course to victory was to destroy the Dominion ' s industrial infrastructure . The Allies agreed they would commit their efforts to the Chin ' toka system , its defenses having recently been thinned to provide additional support for the Romulan front . In late 2374 , the Federation Alliance launched their first offensive into Cardassian space , capturing Chin ' toka after a hard fight . ( ) Although the planned attack against Cardassia itself was not realized , owing to heavy losses taking Chin ' toka , the successful invasion was a tremendous boost to Allied morale . The Allied hold on Chin ' toka was tenuous at best ; the system remained under almost constant attack , making it extremely difficult to reinforce the garrisoned forces . Further offensives were bloodily repulsed ; a Klingon fleet lost thirty percent of its strength attacking Monac IV . ( ) On other fronts , the Allies enjoyed greater success . Elim Garak began working for Starfleet in an unofficial capacity breaking Cardassian military codes ; one such breach enabled the Allies to retake the Kalandra system from the Dominion . ( ) While the Allies consolidated their new front , General Martok launched a deep penetration raid into Cardassian space that damaged several key military targets . ( ) In 2375 , the Federation learned of a development that would ultimately help determine the course of the war : a deadly morphogenic virus had infected the Great Link . Despite the Dominion ' s technological prowess , they were unable to find a cure , and it was determined it would only be a matter of time before the Founders would die . ( ) It was later discovered that the virus had been engineered by Section 31 , a rogue branch of Starfleet Intelligence . Although Julian Bashir did find a cure , the Federation Council decided to withhold it from the Dominion for strategic concerns . Some protested this act as abetting genocide . ( ) Cardassian rebellion . " " Legate Damar may be the key to saving the Alpha Quadrant . " " Meanwhile , the Alliance ' s slowly encroaching front - line had begun to seriously strain relations in the precarious Dominion - Cardassian alliance . The Founders and their Vorta underlings tended to rest blame upon the Cardassian military for the defeats on the frontlines , an accusation that Legate Damar found particularly galling . Many Cardassian soldiers grew distrustful and resentful of the Dominion , while the Dominion continued to erode Cardassian autonomy . Seeking to rescue the war effort , in mid - 2375 , the Dominion conducted secret negotiations with the elusive Breen Confederacy to propose a military alliance ; negotiations which the Cardassians were not privy to . The Dominion granted the Breen unspecified Cardassian territorial concessions in exchange , concessions which Legate Damar had neither seen nor agreed to . His objections were summarily overruled . ( ) Damar grew concerned with further Allied advances , specifically the garrison of the Eleventh Order on Septimus III , which would fall without Jem ' Hadar assistance . The Dominion refused to render aid , regarding it as an acceptable sacrifice . The Klingons subsequently invaded the planet and massacred the garrison . This action finally spurred Damar to rebel against the Dominion . ( ) The Breen Confederacy entered the war in late 2375 with a bold raid on Starfleet Headquarters , sending shock waves through the Alliance . Now able to mobilize a large fleet to carry out offensive operations , the Breen - Dominion Alliance launched a massive counter - attack against the Chin ' toka system . The battle would prove to be the worst Allied defeat of the entire war ; of the 312 ships engaged , all but one were destroyed . However , they could not press their advantage , as soon after , the Cardassian Liberation Front attacked the Dominion military installations on Rondac III , diverting vital resources from the front . ( ) The only Allied warship to escape the Breen energy dissipator s at Chin ' toka was a Klingon warship , the , owing to a chance modification of the ship ' s tritium intermix . General Martok ordered the modifications across the entire Klingon fleet , and had 1 , 500 warships ready for deployment the following day . With the Federation and Romulan fleets effectively useless in the interim until a countermeasure could be developed , the Klingons were left with the daunting task of holding the front - line against the Breen - Dominion Alliance . ( ) However , the Allied defensive efforts were soon jeopardized by Chancellor Gowron , who believed his political position had become threatened by Martok ' s popularity in the Empire . Gowron took direct command of the Klingon fleet and repeatedly ordered Martok on hopeless attacks , intending for him to be killed or disgraced . With the safety of the Alpha Quadrant at stake , Benjamin Sisko ordered Lieutenant Commander Worf to deal with Gowron . Worf directly challenged his leadership , and slew him in single combat . Worf then proclaimed General Martok as the next Chancellor of the Klingon High Council . ( ) Meanwhile , the Federation Alliance saw a strategic opportunity in the Cardassian rebellion to keep the Breen - Dominion Alliance constantly off - balance . The Federation supplied replicator s , weapons and food supplies to the rebels , and dispatched Kira Nerys to train Damar ' s troops in guerrilla tactics . ( ) The Cardassian rebels began carrying out a number of sabotaging attacks on Dominion ships and military installations , and were able to deliver a functioning Breen energy dissipator to the Allied forces . ( ) Unfortunately , however , the success of Damar ' s revolt was short - lived . Gul Revok , who allegedly wanted to defect to the rebels , betrayed them to the Dominion . Jem ' Hadar and Breen ships rapidly destroyed all eighteen rebel bases , ending the organized resistance against the Founders ' rule . ( ) Invasion of Cardassia . Although the Cardassian military rebellion had ostensibly been crushed , Starfleet and Romulan engineers were able to develop a countermeasure to the Breen energy dissipator , thus denying the Dominion their one major tactical advantage over the Allies . Facing a renewed counter - offensive on a wide front , the Dominion - Breen forces withdrew from all conquered territories and established a fortified perimeter within Cardassian space . Their hope was that the Allies would balk at the cost of breaching the perimeter , giving the Dominion time to rebuild . While containing the Dominion within its present borders was a tempting move , the senior Allied commanders argued the Dominion could not be afforded any respite . Instead , the Allies would mobilize all their available ships to launch a single , decisive strike against the heart of Dominion power in the Alpha Quadrant : Cardassia . ( ) On Cardassia itself , the remnants of the resistance had not been idle . The bold revolt , though ultimately defeated , had left a scintillating impression upon the Cardassian people . Buoyed with this knowledge , Damar , Garak , and Kira Nerys successfully bombed a Jem ' Hadar barracks , rallying the civilian population into a popular uprising against the Dominion . Meanwhile , the Allied fleet crossed into Dominion space and engaged the Dominion - Breen forces in battle . Concurrently , popular revolt on Cardassia sabotaged the planet ' s power grid , cutting off transportation and communication systems , causing a planetary blackout . The fleet defending Cardassia was completely cut off from Dominion Headquarters . In retaliation , hoping to discourage further attacks , the Jem ' Hadar destroyed Lakarian City , killing two million civilians . Instead , it had the opposite effect ; the Cardassian military abrogated their alliance , fracturing the Dominion lines , forcing it to retreat . Infuriated , the Female Changeling ordered the Jem ' Hadar to exterminate the Cardassian population . While the Jem ' Hadar rampaged across the planet , the Dominion - Breen fleets in orbit of Cardassia were ordered to fight to the death , ensuring only a Pyrrhic Allied victory . As the Allies laid siege to Cardassia , rebels breached Dominion Headquarters , capturing the Founder . Odo convinced the Founder to surrender rather than fight ; in exchange he would return to and cure the Great Link of the morphogenic virus . The Founder agreed , and the Dominion forces surrendered ; the first time it had ever done so in battle . ( ) Aftermath . The instrument of surrender , the Treaty of Bajor , was signed on Deep Space 9 between representatives of the Federation Alliance and the Dominion several days after the surrender at Cardassia . The treaty stipulated the Dominion would affect a complete military withdrawal to the Gamma Quadrant , while Alpha Quadrant territories were reverted to their boundaries as of stardate 50564 . 0 , just prior to the Dominion ' s initial incursion into the Alpha Quadrant . ( ) The Dominion War significantly shifted the power dynamics of the Alpha Quadrant . The Cardassian Union had collapsed as a major power in the quadrant ; over eight hundred million civilians had been killed by the Jem ' Hadar in mere hours , in addition to over seven million troops during the war , and Cardassia Prime had been severely devastated . The Breen Confederacy had shown both its impressive military and technological capabilities and its desire for violent expansion . The Klingon Empire , having previously suffered heavy casualties in the conflicts with the Cardassians and the Federation , was projected to focus on recovering from the war for a decade . The two remaining major powers were the Federation and the Romulan Star Empire . Romulan relations with the Federation declined after the war , with the Federation embargo on Romulan goods reinstated . This resumption of pre - war attitudes would last until 2379 , when a " coup " led by noted Dominion War commander Shinzon of Remus led to a brief conflict , and Shinzon ' s defeat to hope for improved relations with the Romulan Empire . ( ; ) In the Gamma Quadrant the order of the Dominion was maintained when Odo , fulfilling his pledge to the Female Changling , did indeed return to the Great Link and thus cured it of the morphogenic virus . ( ) Appendices . Background information . Ira Steven Behr and Ronald D . Moore were the writers most involved with the creation and development of the Dominion War . Rick Berman wanted the war to be over within three or four episodes at the most . Behr and Moore knew the series would never be able to wrap up the war in that many episodes . Berman also criticized the " depressing " and " violent " stories . Moore later said " " It ' s a f _ _ _ in ' war ! What do you mean it ' s too violent ? ! " " Armin Shimerman had hoped to have seen the Ferengi involved more in the Dominion War arc . Shimerman commented : " " It would have been very interesting to see how people made profits off of wars , to see a black market during the war , to see how the Ferengi , who were basically neutral during the war , behaved . We did a bit of that but we didn ' t delve into that as much as we could have " " . ( " The Once and Future Ferengi : Armin Shimerman Reflects on Quark " , ) Majel Barrett criticized the arc in a letter published in , claiming that Gene Roddenberry would have never approved of a continuing war in a " Star Trek " series . Berman has espoused similar sentiments , noting that his opposition " " was all based purely on the fact that Gene had been very specific to me about not wanting " Star Trek " to be a show about intergalactic wars , interspecies wars . He didn ' t want it to be about humans fighting wars against other species . " " Responding to the former , Moore admitted , " " She ' s probably right . It would ' ve been very hard to argue Gene into going this way and maybe he ' d have never gone for it . However , I would ' ve still argued for doing the Dominion War with him and if he ' d rejected it , I would ' ve thought he was wrong . I respect Gene and his work , but I don ' t think he was always right and I ' m not going to pretend that I do . The Dominion War has been one of the better storylines we ' ve come up with whether Gene would ' ve agreed or not . " " Bjo Trimble commented : " " I feel that Gene might have come to like DS9 , had he lived to see it . There might have been some changes . Majel recently said that GR would have hated the war in DS9 , but frankly I am amazed that she cannot see the same theme in much of what Gene did , including his recent " discovery " of " Earth : Final Conflict " . The only reason there were not full battles in early " Trek " is lack of funds to pull it off , and lack of technology to show it . Otherwise , GR would certainly have added it ; he knew what audiences liked . I don ' t know about " Voyager " ; I can ' t see where it ' s going , and I don ' t feel GR would have liked that . I don ' t think he would have liked the last couple of movies ; they were very far removed from the " Trek " Gene came up with " " . The Dominion War was directly referred to on three occasions outside of " Deep Space Nine " : , , and . Apocrypha . In " Rising Son " , it is revealed that the inhabitants of the Gamma Quadrant refer to the war as the " Quadrant War " . The war is frequently mentioned in Pocket Books novels and reference books , and there is also a section on it in the " " .