Can ROTW sanction Iran by giving it zero internet access even to "elites" by refusing to peer.

You’re proposing a world wide agreement even by their allies? Like they can just tunnel their traffic through Russia or China.

You could try to bifurcate into allied and non allied, but even that would be flawed, especially in countries like the USA where it becomes a first amendment right to try to ban such connectivity. It’s very hard to kill the Internet in terms of connecting peers - that’s kind of the point of its design.