Giovanni Basta, this was a gripe of Putin's but not the primary reason why he attacked Ukraine.
It's mobster stuff.
Putin wanted Ukraine subjugated and to pay rent. When Ukraine wanted out of this relationship, Putin first threatened; when this failed, he assaulted Ukraine. When Ukraine fought back and could not be subjugated, Putin decided it had to be killed and treated as if it had never existed.
I invite you to read "Time for America and NATO to Act?"
Many thanks.