While I agree that such hypotheticals arent particularly useful, I will strongly disagree with the rest of your post.
Bush II did want to offer Ukraine and Moldova NATO membership in 2008, so it's incorrect to claim that membership was never on the table.
His proposal was shot down by Merkel, who rewarded russia after the annexation of Crimea in 2014 with Nord Stream II.
This is not a matter of bombing Moscow, during the invasion of Crimea, Ukraine's asked for any support in attempt to fight back russia's annexation, these request were completely rejected.
Poland and the Baltic nations actively tried to warn Germany that russians aren't going to reject genocidal imperialism just like that. These warnings were ignored primarily due to corruption (true of other countries like Austria) but also due to a tendency to white-wash russian crimes and a little bit of racism too.
Merkel and Obama were both corrupt, cowardly and fundamentally unreliable individuals.