Moon is a harsh Mistress, by Robert Heinlein.
It sucks being at the bottom of a gravity well when your adversary can throw rocks at you.
Again, we will see the nature of their facilities and take them out long before a threat is realized. We will also have about three days to track the rocks by high power radar and intercept them at high altitude. The smaller fragments will burn up in the atmosphere. I haven't read the book but it seems Heinlein missed something.