There was never anything other than the elimination of Ukraine on his agenda.
When the leader of a sovereign state stands up and declares another sovereign has no right to exist, then follows it up with an invasion of the enemy's territory, there is only one possible way to interpret the intent. Couple that with Putin's reading of the Russian poet who stated that Russia must never lose the Ukraine, and if there is a danger of it happening then it must be brought back into the fold by whatever means are necessary, then I fail to see what ambiguity there is in his actions. I just hope that the west is thinking coherently enough to realise that if he goes through Ukraine, then he will also feel compelled to come to the aid of the Transnistran enclave in Moldova. Securing a safe corridor to Kaliningrad anyone? In his ideal world, Russian control would be as in the Cold War.
The only way to stop this is to give Ukraine sufficient arms to enable them to force the Russians out and stick with them for the long term if we are not prepared to put boots on the ground. We need to stop clutching at straws in the hope that he will be satisfied with territory gained and stop because dictators always want to expand their control. The hope that he might be toppled internally will take time that Ukraine doesn't have.