I agree. The main theme(perhaps only theme) of the trailers is "Morals are nice, but this is war." Especially the third trailer. Every character statement has to do with choosing to abandon your principles in order to save the Federation.
It's a theme that was always a part of DS9, from the Maquis, to Sisko and the Dominion, to Sloan, etc. Sloan says the work he does is necessary for the Federation to continue be an "enlightened" society.