It would be the equivalent of EMPing our entire planet. By that point civilizations will depend on other planets. Hell, Qo'Nos had to come to the Feds with hat in hand when they lost access to a moon. And what about any neutral warp-faring populations in the 'dead zone'?
Also, any thoughts about the Dominon holding back their own super-weapons goes out the window. I know it seems they didn't play by any rules, but I have to think with all the hand-wringing over the Changeling Virus, that they played by a few at least.