My guess is that it was the decision of Ukraine to pursuit joining EU and potentially NATO (and potentially having US forces there) and Russia understanding that it is out of options to prevent this by peaceful methods like bribing politicians, propaganda, appealing to voters sympathetic to Russia at that moment etc.
This happened in 2014. Also, if you remember, before starting the war Putin demanded that NATO stops expanding to the East, but was ignored [1].
So basically Russia wasn't willing to lose a large neighbouring country to US.
technically, if that was cause, nato thing. were is retoric about 2 north countries joined now? why so inconsistent?
so russia not willing to loose sovereign independent country to which it promised to secure it to be so?
how one can loose what he does not have nor owns?
By "losing to US" I meant Russia is not willing Ukraine to have pro-US (instead of pro-Russia) government, and potentially having US military there (US for some reason is trying to put its military bases and missiles everywhere around USSR/Russia since WW2).
This happened in 2014. Also, if you remember, before starting the war Putin demanded that NATO stops expanding to the East, but was ignored [1].
So basically Russia wasn't willing to lose a large neighbouring country to US.
[1] https://en.wikipedia.org/wiki/December_2021_Russian_ultimatu...