Not going to curtail jack shit if you haven't left your homeworld. There's a large Universe out there, it's absurd to imagine muscling other races out without a wide-reaching presence, and that demands colonization.
So says the reflexive expansionist, too big for its britches, about to be taken down a peg via novas induced on the suns of its homeworlds by unidentified offended parties.
It is a dangerous galaxy, out there. Step carefully.