Federation - Cardassian War The Federation - Cardassian Wars , known in the Federation as the Cardassian Wars or Border Wars , were prolonged conflicts between the Federation and the Cardassian Union , which started as far back as 2347 and lasted into the 2350s . ( Smaller skirmishes , not officially considered part of the wars , continued into the 2360s . ) The ensuing stalemate by the mid - 2360s advantaged neither side in firepower or territory . A 2367 truce enforced an end to hostilities but left key questions unresolved ; the finalized treaty , unsigned until 2370 , formed a demilitarized zone between the powers , creating a new border and clarifying claims to planets such as Dorvan V . ( ; ) The wars raged in a series of conflicts of various sizes as the two powers struggled to protect their individual interests . A major incident was the Setlik III massacre . The Federation starship , under the command of Captain Benjamin Maxwell , was the first vessel to respond to the colony ' s distress call s . The " Rutledge " went on to become involved in other conflicts during these wars . Miles O ' Brien and many members of the ship ' s crew exhibited signs of xenophobia towards Cardassian s thereafter . ( ) The , commanded by Captain Raymond , also saw extensive combat . ( ) Prior to 2355 , the was involved in a truce offering by the Federation in sector 21503 . After making contact with a Cardassian warship , Captain Picard lowered the ship ' s shields as a gesture of good will , but the Cardassian commander ignored the gesture and disabled the " Stargazer " s weapon s and impulse engine s . The " Stargazer " managed to regroup and flee . ( ) While Kathryn Janeway held the rank of lieutenant , she was a member of an away team defending a Federation outpost from Cardassians during the border conflict . The Cardassians fought for the outpost for weeks , and at one point , ended up in a three - day long firefight . In the end , Starfleet secured the outpost and all members of the away team were decorated by Starfleet Command . ( ) Much of the fighting went on in the area of space that later became the DMZ . During the war , gravitic mine s were deployed near the region later known as the DMZ . ( ) The Cardassian Union pushed into Federation space , and Federation systems such as Minos Korva were disputed territory during the wars . In 2369 , two years after the established truce , the Cardassians unsuccessfully attempted to take the system . ( ) Members of Starfleet further feared that the Cardassians would try to annex the Igo sector in that year . ( ) Losses during the wars left deep scars on both sides . For instance , Gul Evek lost two of his three sons during the Cardassian Wars , and Captain Benjamin Maxwell lost his entire family . Starfleet officers such as Will Kayden and Raymond Boone died during the war . Popular Federation ambassador s Spock and Sarek ( Spock ' s father ) disagreed publicly over the Cardassian Wars , which led to a serious divide in their relationship and family . ( ; ) Tensions remained between the two expanding powers . Many seasoned veterans from both sides were called upon by their respective governments to face each other again during the Dominion War that began in late 2373 . Years after the war , Miles O ' Brien noted that field ration s was the only thing he missed about the Cardassian front during the war . ( )