Comment by belorn

IP address space and the domain name system are centralized with defined roots, and IANA/RIPE could have removed russia from the internet a long time ago. A primary reason why they have not done this is what happen after the war is over, at which point the west would have Internet with root A, and Russia would have Internet with root B, and recombining A and B would be a very difficult and likely to last longer than transitioning completely from IPv4 to IPv6.

If there is a central and core theme with the Internet and all the organizations that manage the core infrastructure is the effort to avoid splitting the root.