So I am biased since I am from Romania, but IMo is clear Russia wants the natural resources and the strategical position from the Black Sea not to defend itself from the small easter European countries but just from pure greed, like in a cmputer game you rush to grab the natural resources to prevent the others to use them and grow, after you grow you invade and destroy their shit until they surrender. Defensive alliances would make sense if you want to protect yourself and this is what the eastern european countries want from NATO.