Mostly political. You could presumably do the detonations with the moon in between for a while, and it's not like space outside the Van Allen belts is particularly low energy, either, so GEO satellites are shielded.
i hate it when problems are "political" - or more correctly, that the general public's ignorance and fear retarding progress.
If I had ~10k nuclear weapons, I'd no longer have political problems.
I think you would suddenly have a great many political problems.