[ben_w]

The USSR asked to join NATO, which was quite funny to learn about.

Russia-NATO relations were pretty good, even heading (slowly) towards such membership under Putin in 2000.

Unfortunately, Putin didn't like GWB leaving the ABM treaty, and did like having the old USSR back, so aggression and all else as you say.

[Iwan-Zotow]

Perhaps, he saw the result of NATO aggression against Serbia?

[ben_w]

"Russian paratroopers seized Slatina airport to become the first peacekeeping force in the war zone" - https://en.wikipedia.org/wiki/NATO_bombing_of_Yugoslavia

Which was a surprise at the time, and left some convinced it was a UN rather than NATO operation.