Can you say that Biden's rhetoric has not been a factor? When Biden signaled he was going to push for Ukraine to join NATO, that was the most provocative statement he could make to a paranoid and defensive Putin who above all things will not be seen as being weak. And then demonizing and vilifying Putin to the world further stimulated his resolve not to appear weak. Couple that with Obama and Biden's non response to Russia annexing Crimea, Putin calculated they were weak and do little more than lip service.
Trump was far wiser in dealing with Russia. He understood that Putin is no different than most people in wanting a legacy of greatness, nobleness, doing good. So he appealed to Putin's 'intelligence', status and such--Trump has been condemned for that mightily--and recognition of his position in Russia while at the same time convincing Putin that if he overstepped his authority, the U.S. response would not only be certain, but it would not be weak.
It is the difference between being political and politically correct and being smart/effective. The Trump doctrine gave us the closest thing to world peace than any of us had ever experienced in our lifetimes.