The Cardassian Occupation of Bajor showed the darker side of the Star Trek universe, but its history was actually quite complicated. Starting when the Cardassian Empire seized control of the peaceful planet of Bajor, the Occupation completely changed the trajectory of the planet and the Federation as well. The Occupation showed that the Federation's ideals of peace and harmony weren't shared by all, but Starfleet's inactivity was also a dark mark on their history. Though the Occupation did eventually end, the repercussions continued to rock the Alpha Quadrant for decades after the Cardassians withdrew from Bajor and was one of the defining storylines of Star Trek: Deep Space Nine​​​​​​.

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