When the world splits in half, we will not want hard borders between the two. Buffer countries, slightly friendly to both sides, could be the answer.
A buffer country could (unofficially) facilitate illicit connections between both sides, with trade, ideas and people smuggling.
Ukraine is in the news lately. They want to join the EU. Russia wants a buffer country. Russia’s only option is to invade them, because Ukraine being a formal buffer country is not on offer.
Suggestion: Finland, Estonia, Latvia, Lithuania, Belarus and Ukraine form a combined buffer.
Georgia and Azerbaijan are stuck between Russian allies (East), so ignore them…
The buffer has these aspects:
- Joint trade agreements with the EU and Russia
- A NATO like military arrangement
- Residency rights for EU and Russian people
- Agree to not get in the way of any trade/pipelines etc between the EU and Russia
- A commission on any trade between the EU and Russia, like 1%
In a full East/West split, the buffer can facilitate trade while neither the East or West have direct contact with each other.