Looking at warfare cheap (noncomplex?) plentiful armaments often carry the day.
The Moon is a gravitational high ground in proximity to Earth.
Launching a rock that will land on Earth with all the energy of a nuclear bomb is a daunting prospect.
Also from the Moon going out to redirect a nearby rock/asteroid to do the same is much more feasible.
It's an easy place from which to tyrannize Earth.
Better to have several national/global parties in contention there than one.
The worry is when those parties might all collude in the same objective.
But it is contingent on viable operations there, but it could be completely robotic including AI controlled.
Not worried?
Tell it to the dinosaurs.