Putin has stated many times that he thinks Ukrainians and Russians are "one people". He has stated many times that Ukrainian land is historically Russian.
He delusional revisionist version of history is to blame. Putin thinks he has the right to rule Ukraine. It would pay you to read Putin's 5000 word essay where he spells it, albeit delusional, his version of reality that he thinks entitles him to rule Ukraine. It is clear you have not read this essay yet.
Putin has tried to conquer Ukraine politically, that failed. Putin is now trying to conquer Ukraine militarily, this has also failed.
Putin and the Kremlin have a very very long history of meddling in Ukraine and trying to erase Ukrainian identity and culture.
The "Nato expansion" lie is simply a slogan tailored for those with the mental acuity to only be able to parrot such a slogan.
Fact-checking Putin’s claims that Ukraine and Russia are ‘one people’ (rochester.edu)
Putin says parts of Ukraine have been Russian since 'time immemorial.' That's a one-sided view of history. - Poynter
