Flag Territory In the mirror universe, the Cardassian Union was an interstellar political entity controlling Cardassia and its territories. For much of the 24th century, it was one of the two dominant powers in the Alpha Quadrant as part of the Klingon-Cardassian Alliance. The Cardassians were a generally militaristic race. In the late 2270s, the Cardassian Union was engaged in numerous border conflicts with the Tholian Assembly. At Emperor Spock's order, the Terran Empire provided ships and small arms to the Cardassians in order to aid them in their wars against the Tholians.