As of the end of WWII, Stalin had regained all the land Russia lost at the end of WWI, except for Finland and a small area at the eastern end of the Black Sea, just south of Georgia, which Turkey acquired.
Possibly their NATO membership will protect the Baltic countries from re-annexation, and maybe Putin will let go some of the mostly-Muslim republics of central Asia, but he may figure Belarus, Ukraine, Moldova, Georgia, maybe Armenia and Azerbaijan, and perhaps portions of Kazakhstan are fair game for reinclusion in his empire.
The Baltics are caving from within.
Latvia is the start with the Russian population that is pro-Kremlin getting voted in positions of power. It took a while before they could get their Latvian citizenship to vote, but they are now voting.
Lithuania may be the saving grace. But like the E.U., they do need Russia’s natural gas as does Poland...
NATO will watch as Gazprom continues to remind Europe who supplies a large portion of their natural gas..
When you have Turkey playing with Russia on exercises, you have to ask, how strong is NATO.
Times have changed with China, Iran and Russia...