Establishing an actual colony on the moon instead of just a temporary outpost will require a huge amount of basic scientific research. This goes way beyond just economics and politics? For example how do we keep people healthy and prevent bone mineral loss and muscle wasting in low gravity? How do we mitigate the effects of increased background radiation? Any real sustainable colony will need people working out on the surface so they can't just hide in underground tunnels.
We could easily have done that research in the 20 years after the cold war. These are not research that requires state of the art technology (except for radiation shielding which requires good materials science). But we didn't, because there was no immediate demand.
I would even say that underneath the political and economic challenges is a lack of will in the first place.