The Federation is not merely a democracy but also a place of law and order where kidnapping, theft and murder are considered to be crimes. And no, they are not human values but universal values in the Federation. If the Andorians would consider it as appropriate to sacrifice a bunch of aliens to live longer they would be the Andorian Empire and not members of the Federation.
About the Section 31 interpretation, they might have been involved but in this case they did a lousy job of gathering intelligence about the So'na and in the end the Federation council permitted Dougherty's mission. So all Section 31 could have done was misinformation, manipulating representatives and so on.
T think it is more sincere to admit that the Federation was perfectly willing to commit an atrocity until Picard interfered. That's an old pattern from TNG, nasty Admiral violates Federation principles, Picard idealistically fights for them. Doesn't become more black and white than such a simply morality tale.