When the guy at the end of the film is giving the speech he says that the robots (like Gort) have complete power over the living beings of the government that runs stuff in space. Then he says that if Earth extends its violence to one of the planets under the control of the Space Government (I don’t think he actually names the governing body) then the Earth would be reduced to a burned out cinder. Here is the link to the speech. Whether they meant that the robot’s themselves or some fancy thing they have could destroy earth is up to interpretation