Technically, Ukraine joining NATO would have also put Russia at the border of NATO countries. And it seems obvious to me that it would prefer a neutral buffer zone, instead of encirclement. Removing the first option from the table in 2013 forced the question of the second one.
I can't see how any of this could have worked out well, starting from the moment that Ukraine membership in NATO became a serious political subject.
> Technically, Ukraine joining NATO would have also put Russia at the border of NATO countries
Technically, Ukraine’s entire population being whisked into another dimension and its borders being impassable walls of force would also put Russia at the border of NATO countries (as would, for that matter, NATO not expanding after 1949), because Norway (1949), Lithuania (2004), Latvia (2004), Estonia (2004), and Poland (1999) all exist (and Lithuania and Poland surround a non-contiguous piece of Russia, even.)
And that's just counting land borders, otherwise you have to also consider the USA (1949), Turkey (1952), and Bulgaria and Romania (2004).
I can't see how any of this could have worked out well, starting from the moment that Ukraine membership in NATO became a serious political subject.