>>At the end, this was not to be. The TCP/IP specification became dominant.

Speaking as a datacomms guy who lived through the protocol wars, there were a number of years in which each protocol stack adopted ideas from the other, so the TCP stack has a lot of what made OSI different - and vice versa. With IPv6 the primary difference is in where the layer boundaries are drawn.

We saw something very similar happen with mobile phone stacks. GSM and CDMA were very different (mostly around where the 'intelligence' for congestion control lives) - and now LTE is essentially both of them together.

If Russia or China wants to disconnect completely, the simplest thing would be to start assigning their own IPv4 ranges, keep their IPs inside, duplicate ones from the outside via BGP (Border Gateway Protocol) are kept out by defining them as non-routable ranges and block v6. Or they could 'airgap' - just cut the physical connections. They haven't done either of these things. I would guess that it's because they see some value in connectivity, even if it's for meddling in elections (Russia) or industrial espionage and IP theft (China). Personally, I don't see a lot of value for the rest of us in either of those behaviors and view them as parasitic on the rest of the world.