Explanatory chart

Stationed in lunar orbit, there is a ring of automated battle stations, similar in concept to a SSBN nuclear ballistic submarine.
This is an explanatory drawing showing the main parts.
They can be delivered with current technology, but are designed to do war against lunar surface installations, making new craters by the way.
They are too far away to launch an undetected attempt to bomb the Earth, but lunar objectives are a more realistic ones.
They need regular human presence for refuel and refurbishment, as it depends on fuel cells instead of voluminous solar panels for energy supply.