I personally think that Sterling is saying that humans' thoughts and words can be as deadly as bombs and wars. I agree with this, as many people can say and think extemely hurtful things, and humans, for some strange reason, always seem to want to accuse someone else of doing something they may or may not have done, before there is evidence. I think the story The Monsters Are Due On Maple Street very well demonstrates this. I think that "children yet unborn" means all humans to come, and that they will be effected in some way, by the dangerous thoughts and words of themselves, or other humans.