It seems that many people have forgotten this, but at first and for years Putin was very pro-American, pro-Western, pro-EU, pro-modernization, and pro-NATO expansion into former Soviet Republics. He was positively glowing with approval when the Baltics joined. I have quotes if people have forgotten.
I don’t believe Putin himself as an individual cares about Ukraine, Georgia, Syria, the EU, the Western values, or anything of the kind. I think he cares about palaces, luxury, whores, and exotic animals.
He must have noticed, though, that unless he invaded, his ratings plummeted and an opposition movement grew. The moment he invaded somebody, the ratings soared and everybody, including the opposition, began to adore him. So he does whatever he needs to keep his palaces, exotic animals, and whores. The whatever happens to be invasions, so that’s what he does.
The largest country on the planet is populated by 120 million people, 88% of whom aren’t happy unless somebody is getting invaded in their name. Putin is just a symptom.