Sisko is my favorite. I don't think it was going off the deep end as much as using the same strategy the US used by nuking Japan. Japan had no chance at that point and continuing conventional war would have been more costly in terms of lives lost and property damage. Using nukes crushed any hope they had of continuing the war and have their prideful government an out that preserves their ego.

In DS9, it sent the message that the federation is can and will annihilate the dominion to defend themselves and the god complex of the changelings was pure delusion.