The only reason Ukraine ever has any interest in joining NATO was for fear of Russia attacking them—-again—like they are now. And now, thanks to Putin, there’s a very good chance Finland will also join NATO.
You know what would have been reasonable? For Russia to leave its neighbors in peace and continue building economic ties making conflict with them costly to everyone. The ties that had built up since the fall of the USSR had done more for Russian security and all their military spending combined, and Putin flushed it all away.
You are absolutely correct that would have been the wisest course of action for Russia if it was concerned about security. Europe and NATO had zero interest in ever going to war with Russia, or with anyone else for that matter.
But apparently, Russia wasn't concerned about threats to Russia itself. It was concerned about "threats" to its long-term ambition of reconstituting the Soviet Union. If a country became part of NATO, it could no longer be bullied by Russia, and Russia saw this as an intolerable limit on its desire for hegemony.
But they've really screwed themselves now, haven't they? As you said, the best path forward for Russia was deeper economic ties with Europe and peaceful coexistence. Now, regardless of how this war ends, the nations of Europe are no longer going to trust Russia about anything. They'll never threaten Russia's borders, but they are going to be extraordinarily reluctant to engage in long-term business or economic relations. In terms of a relationship with Europe, Russia will largely be on its own.
That's pretty much the exact opposite of Russian geopolitical strategy since Peter the Great, and it was all wrecked by Vladimir Putin.
Nice job screwing over your own people, you idiot.