Their invasion, or more accurately HIS invasion. While I appreciate your effort to understand the genesis of human violence, I think you ignore much basic reality.

Some people employ violence for personal gain, for personal satisfaction, or to make themselves feel powerful. They don't necessarily lack interpersonal skills, conflict resolution skills, or negotiation skills, they are simply uninterested in resolving conflicts that they are using to get what they want.

The "problem to be solved" in Ukraine is that putin wants to POSSESS Ukraine, and is willing perhaps even eager to employ violence to get it. Assuming that there is some sort of negotiation that will change this desire is foolish. Like so many other damaged and twisted violent people, putin kills for pleasure, for gain, and for personal re-affirmation.