^ No, but wandering in there and taking planets and starting colonies on them wherever wouldn't be looked upon favourably by anyone, esp. as hostile as we in the Dominion are.
If the Dominion had wanted the Federation to stop, they should have said so.
Conversely, the Dominion pouring troops into Cardassian space *was* inherently dangerous to the Federation, who had every right to stop it.
Or, by your own logic: Why should the Dominion be allowed to enter the Alpha Quadrant with impunity, but the Federation not be allowed into the GQ?