It could be a functional requirement for humanity to participate in space. Without the ability to orbit over other countries, nobody can have any type of satell

It could be a functional requirement for humanity to participate in space. Without the ability to orbit over other countries, nobody can have any type of satellite. Once you've established it's OK to orbit satellites over other countries, the gradient between a weather or communication satellite and a spy satellite might be small enough all relevant stakeholders have agreed to treat them under the same rules. Finally, enforcing 'no spy satellites' using force could invoke Kessler syndrome, so any country with the ability to enforce the 'no spy sats' rule is probably most impacted by the consequences.