I am taken aback by the idea that Section 31 would likely commit genocide against a species that was literally in the heart of the Federation. That is altogether different from committing mass murder against distant peoples of whom practically nothing is known. It's the difference between having your military go out beyond the frontiers and start massacring foreigners and having your military come into your cities and start killing everyone in sight.
This is astonishing recklessness. Am I wrong in thinking that a secretive organization ready to undertake such radical actions without authorization is set for a hard fall?
In WWII the Allies allowed some of their own cities to be attacked because they didn’t want their enemies to know they cracked their communications codes so, they could counter attack on more important targets.
As Odo said in DS9, all great power in the galaxy has their own intelligence force. The Obsidian Order and the Tal Shiar didn’t hesitate to sacrifice their own people for the greater good. Why would Section 31 be any different?