The image you linked were made by a weather monitoring satelite. It was optimised to capture a wide are of the globe. This is clearly not the type of lens you would use to surveil military activity. It is not even the right modality to capture radar signals.
Geostationary orbit is ~36000 km above the surface. Optical surveillance satellites work at altitudes of 200-400 km and already need Hubble-like mirror sizes to achieve the needed resolution. A geostationary satellite with a similar resolution is simply not possible to build and launch in this age. Geostationary also means that half the time you're looking at darkness.
Thank you very much for the answer. (both you and all the other people)
> A geostationary satellite with a similar resolution is simply not possible to build and launch in this age.
I think I will have to read up on that specifically more. I was aware how far GEO is, but I don't understand what makes the optics impossible. (Clearly it is as you say, all the sources agree with you.) Thank you!
The image you linked were made by a weather monitoring satelite. It was optimised to capture a wide are of the globe. This is clearly not the type of lens you would use to surveil military activity. It is not even the right modality to capture radar signals.