I'd go 25% NATOs fault. You'll note Ukraine didn't apply to join NATO, was not invited to join NATO so Russia saw it as easy game and invaded.
A problem with the west is they persuaded Ukraine to give up its nukes in return for a bit of paper saying the west would help protect it and then when push came to shove they were wimpy about it.
A problem with the west is they persuaded Ukraine to give up its nukes in return for a bit of paper saying the west would help protect it and then when push came to shove they were wimpy about it.