The acting, the plot, the character development. The ethical struggle in the episode and its resolution and the clear parallels to real world problems. I don't want to spoil it for anyone who hasn't seen it, because it unfurls in such a wonderful way that needs to be seen rather than summarized.
"You have no idea what it's like to be a coward." So much packed into that line: filled with self-hatred and shame, and also respect and admiration for the person in front of him and the people she sacrificed so much for.
I would pay a lot of money to see a political series focused on a sort of Cardassian Reconstruction era. I really ought to read some of the books.
Knowing you could have done something but were too afraid for your own life will eat you up for a very long time.
And the knowledge that it would ultimately accomplish nothing except killing yourself and a few bajorans while trying to escape doesn't help.
Everyone likes to think they'd fight the good fight, resist at all costs, oppose all force.... But ultimately until you're in that situation, you won't know for sure. And you don't want to find out for sure.