Russia's invasion of Ukraine may be partly -- mostly, ostensibly -- about Ukraine, but it could also be an attempt to provoke lots of institutions in the rest of the world into making overly-aggressive counter-responses.
Russia may want the CIA and special forces of European nations, to overreact. It may want Facebook to fail to moderate within Russia's (perhaps onerous, but no less legitimate in standing than of any other country) legal requirements, may want NATO to overstep, may want individuals and groups to get involved to the extent of personal and business risk that they later regret.
Under that perspective, Russia's actions could be a series of provocations almost entirely to demonstrate and document alleged hypocrisies around the globe and to see whether the world is able to counteract those, or whether the general population proceeds with accepting them as matter-of-fact.
This idea makes me scared. There's vast potential to uncover massive wrongdoings and learn about organized, international coercion -- but there's also the chance that those same forces (who are, I'll add, not always restricted by borders, in practice -- even though citizens of all affected countries are) simply win out and become a dominant world order.
But, I don't think you need any complicated theory to explain any of his actions re: Ukraine. He's wanted that country back ever since it broke off from the USSR. He never considered its moves toward democracy legitimate. He grabbed part of it in 2014. His actions have been very consistent on that front -- make plays to control Ukraine and weaken NATO. Finally he's dispensed with the subtlety of cyberattacks and political messaging and just went full in with ground forces.