I’ve said it before, that ds9 is about choices. Kira says to Ziyal at one point that you can only judge people by their actions, not their words. Which I think summarizes the show in a way.
We see that clearly when we think about Garak and Dukat.
They have both done terrible things. They have killed and tortured and both do it “For Cardassia” but also a lot for themselves. They have similar backstories, although one is a politician and one is an administrator in the authoritarian machinery.
But when given a choice - they chose differently. Among other things Garak chooses to help Natima and her students to flee, by killing a Cardassian offering to end his exile. It is hinted that one of the reasons he was exiled was that he let some children, accused of being in the Bajoran resistance, escape. When faced with those children - he chose to release them. He helps the Federation on multiple occasions. He makes bad choices too, like when he follows Tain into the Delta Quadrant and things go totally sideways. But a lot of the time he chooses what he considers morally correct over his own elevation.
While Dukat, constantly, chooses the wrong path. He is given the opportunity to redeem himself again and again. But he chooses the Dominion, he chooses to leave Ziyal to a certain death when she disobeys him, he chooses to align himself with the pah-wraiths, he chooses to abuse his power over his followers and his subjects. He always chooses power over justice, worship before mercy.
