[CapricornNoble]

>>>I can't think of an innocent reason for Russia to be afraid of Nato,

Because in 2007 the US unilaterally decided to base Anti-Ballistic Missiles in Eastern Europe NATO countries. Russia was concerned that continuation of such practices would destabilize Mutually Assured Destruction (by being able to intercept Russian nukes), and potentially signal US intentions to risk a first strike and regimen change operation against Russia. Considering that the US, at that point, had already invaded and regime changed two other countries in just the previous 6 years, it might make more sense why that would color Russia's strategic calculus.

>>>Russia could never have joined the alliance while it was under Putin because it's not a %@$&ing liberal democracy.

When Russia was first floating the idea of joining the EU and/or NATO circa 2001-2003, you could argue Russia wasn't significantly worse than Ukraine in relevant metrics. He only had a handful of suspiciously-dead journalists and potential false-flag bombings under his belt. I don't think they had a crackdown on western NGOs, LGBT rights, or totally rigged elections (Putin had, and continues to have, a lot of genuine support).