I am not convinced that a Putin is a psychopath.
He is simply behaving as all dictators behave, and following his own version of truth.
He is or was convinced from the way Europe has behaved that it is weak, so in his view sanctions were no threat.
He is or was convinced that Biden is too old and weak, by looking in particular the Afghan withdrawal.
He is convinced after the way his military performed in Syria that it will perform well in Ukraine. However, there appears to be a very high level of breakdown, and poor logistical planning, if the stuck convoy, and ukraine resistance is an example.
One wonders if the military has been underfunded or indeed the funding has been syphoned off?
The problem is that this level of incompetence will only encourage him to take even more drastic action, and the question is,- at what stage does the west say “enough” or indeed if at all.
Putin like Hitler will never stop, because like all dictators they are convinced of their world view. Nothing his generals tell him will alter his version of the truth, so he will never stop, until he is stopped.
We need to understand that.