A month ago I speculated that Finland and Sweden might join NATO, a strategic backfire against what Putin had intended. Apparently both countries have already decided to join NATO and will file formal applications this summer. What else might happen as a cost to Russia?
Finland, Estonia, and Latvia might recover the territories the USSR took from them during the 20th century: Karelia, Salla, and Petsamo (Finland); Narva and Pechory (Estonia); and Abrene (Latvia).
The former territory of East Prussia might be divided between Lithuania (the southern part of Kurskiy bay) and Poland (the city Poles call Krolewiec).
The EU has already agreed to admit Ukraine, and perhaps it is reasonable that it not join NATO. The Donbas and Crimea regions should be acknowledged as part of Ukraine in law and in practice, and perhaps the Taman Peninsula should be ceded to Ukraine to ensure that Ukraine has firm control of the Kerch Strait between the Black Sea and the Sea of Azov.
In order to consolidate the EU further, a wise strategy would be to admit more Balkan nations: Moldova, North Makedonia, Kosovo, Montenegro, and Albania. Serbia needs to sort itself out. It might actually join the CIS rather than the EU; but perhaps the internal politics of Serbia will change in coming decades.
If they choose, Bosnia and Georgia should be admitted to NATO (and also Armenia and Azerbaijan, though their mutual hostility might make that infeasible, so I did not show them).
In addition, two countries that have repeatedly struggled for independence from Russia should be recognized: Circassia and North Caucasus (N. Kavkaz in the map). Abkhazians and Ossetians would need to figure out where and how they want to align; I am not showing their possible future dispositions because I cannot eve guess where they might choose to go.
NOT SHOWN: The Kurile Islands (and all their fishing rights) should be returned to Japan, and perhaps Sakhalin as well.
All of the changes speculated in this posting are real possibilities, and they reveal the disastrous cost of aggression in the 21st century (the US is already paying for some of our own foolish unilateralism, but may also suffer more consequences in the future). Russia would still retain access to the Baltic, but only through Finnish and Estonian sovereign waters. Russia would retain access to the Black Sea via Rostov, but only through Ukrainian sovereign waters. The problem, of course, is that Russians would see themselves as victimized no matter how much their leaders choose to inflict violence on others. So this speculative cartography is not likely to lead to a peaceful outcome. But what would lead to a peaceful outcome?
I suppose the slim good news from the Russian perspective is that climate change is melting the Arctic icepack. All the ports on their northern coasts may be ice-free in a few decades, eliminating their strategic need for warm-water ports.