It's an entirely accurate statement that this wouldn't have happened under Trump.The reason I point that out is not because I think Trump did it on purpose by any stretch of the imagination. But this likely wouldn't be happening of Biden had lost the election.
Being the fucking idiot that he was, he stocked his regime with pro-NATO, anti-Russian neocons while personally being anti-NATO and in favor of a better relationship, so his Russian policy was never coherent.
But the Ruskies at least knew he wasn't going to bring Ukraine into NATO.