In war this is done by "weapons"—Luna had none. But weapons, when Mike examined them as class, turned out to be engines for manipulating energy—and energy Luna has plenty. Solar flux alone is good for around one kilowatt per square meter of surface at Lunar noon; sunpower, though cyclic, is effectively unlimited. Hydrogen fusion power is almost as unlimited and cheaper, once ice is mined, magnetic pinchbottle set up. Luna has energy—how to use?