The sovereign countries themselves must get a choice - if they want to join NATO, that is their right, and Russia shouldn't get a veto (nor even a vote) in that. Countries should be free to join/leave the "spheres" at will, not be placed there or given or taken.
And, actually, the whole reason why NATO is at their borders is the Russian insistence of their sphere of influence. If Russia agreed in practice that their borders stop where they are and that they won't ever poke beyond them, then their neigbours wouldn't need to even consider NATO.