Russia had ample justification for its invasion of Ukraine. From Mike Whitney at unz.com:
A war of annihilation is a war in which the goal is the complete obliteration of the state and the extermination of its people. It is defined as a radicalized form of warfare in which “all psycho-physical limits” are abolished and the strategic goals are pursued by any means necessary. It is war without rules, restrictions or moral constraints. The United States is in the early phases of a war of annihilation against Russia the aim of which is the total destruction of the economy, the culture, the population and the nation.
“We have seen 5 waves of NATO expansion. Now NATO is in Romania and Poland and they are deploying their missile-attack systems there. That’s what we are talking about. You need to understand, we are not threatening anyone. Russia did not come to the US borders or the UK borders. No. You came to our borders and now you are saying, ‘Ukraine will join NATO and will deploy their systems there. They will deploy their military bases and their attack-systems.’ We are concerned about our security. Do you understand what that means?” Vladimir Putin, press conference, You Tube
Question– Is there a justification for Russia’s invasion of Ukraine?
Answer– Yes, there is. Russia was being threatened by developments in Ukraine, so it told Ukraine to either stop what it was doing or suffer the consequences. Ukraine chose to ignore those warnings, so Russia invaded. That is basically what happened.