I doubt there is any other "optimal" approach, but do say what you would propose.

There will always be indirect interference anyhow (think social networks, books, press, people talking, tariffs, visas, etc.), so there is some possibility for states to push things in their direction.l

I think imagining there can be some "authority" that could decide when "direct interference" is allowed or not will be a disaster at some point, because even if at first is OK, as a society we don't seem to be at a point where we can have organizations that work well for hundreds of years.