When to look at history and its events, then before massacres or big tragedies, de-humanisation has aslways taken place.
De-humanisation is a process where a group of people has been labelled as something. So instead of individual persons they are being seen as belonging to a group under one label.
Now Putin is calling the Ukrainian government as “fascists”, “ultranationalists”, “extremists”. This has been done to “Jews” in Hitlers Germany. Die Juden. It was not important who were you as a personality. It was just that you were a jew and that was a reason for killing.
Now the result of Putins propaganda is heavy demoralisation of Russian people. They get a label in their minds, whom to hate even without seeing a person.
That kind of action is a strong sign of danger.