I think the important bits are easy to pickup in context. There is a war and it’s not going well. Sisko is trying to bring a powerful neutral party into the war and is willing to do very questionable things to do it.

As a Star Trek fan I had given up on DS9 during the original airing of the first season. Latter I caught Pale Moonlight by chance and it impressed me enough to watch some more. Then I went back and watched all the earlier stuff. Now it’s my favorite Star Trek.

When I first saw it I knew Star Trek quit well but had no idea what was going on in DS9 and had no trouble following the story.