Come to think of it, after writing that about The Moon is a Harsh Mistress I read a tweet (that I can't find now) where someone said that the opening up of a "Moon city" is just an way to paper over the militarisation of the Moon by the USA, in that they can then quickly create some sort of a bombardment system on the Moon whereby they can launch large Moon bolders at the Earth to target enemy nations, simar to what the Lunar Rebels did in Heinlein's novel. It's a crazy idea, but at this stage, I wouldn't put it past some people in the Pentagon and other think tanks to think along those lines.