Winston Churchill famously said, "I cannot forecast to you the action of Russia. It is a riddle, wrapped in a mystery, inside an enigma; but perhaps there is a key. That key is Russian national interest."
I knew about the first clause long before I learned that Churchill also thought the mystery could be solved, that the riddle had a key.
And I think that throughout the Soviet Union period, Churchill was largely correct: Russia might appear to be acting strangely, but it is always trying to gain some advantage for itself. It is always trying to secure its interests in a world it perceives as full of enemies.
But I think that's no longer true, if it ever was true to begin with. Nothing Russia has done in the past year or so seems like a rational application of the principle of self-interest. Moscow is like a bully that not only does things for no benefit, but only because it can, but even continues bullying even when it's against their interests to do so.
Even if we assume Putin is acting out of some desire for historical greatness, it still doesn't explain how he's chosen to go about it. In fact, whatever motivation we ascribe to Putin's actions, they don't explain why he's taking those actions in the service of those motivations.
Russia truly is a mystery, wrapped in a riddle, inside an enigma. But - apologies to Churchill - there is no key.
I cannot forecast to you the action of Russia. All I can tell you is that whatever it is, it will be stupid and counter-productive to its larger interests.