When I asked for concrete evidence that Western actions threatened Russia and I needed to read two whole books, something doesn't add up. You should easily find evidence, like the collective Western countries destroying Russian infrastructure, hacking of Russian organizations, killing of civilians... something.

Especially when one of which highlights Russia shooting down the flight MH17 and killing 300 people, very much like the shooting of the Azerbaijan airplane which Russia denied emergency landing - probably in an attempt to make it crash to destroy the evidence. With the flight MH17, there were pictures taken by Russians proudly on top of the debris, and this time around medals were awarded.

As for Scott Horton's book, he sure knows how to repeat Russian propaganda points, including the "not one inch of NATO expansion" lie, in the classical conspiracy theory fashion, just the description says it all:

"Over and over, U.S. government officials and their mainstream media allies called Russia’s 2022 invasion of Ukraine an “unprovoked attack.”"

It's funny that a lot of these "Russian mouthpieces" have something in common: only Russia "the victim" and the USA "the aggressor" have agency, and the remaining sovereign countries and their millions of citizens are NPCs, with no will or History of their own.

If you want to have a basic understanding of why Russia pushed countries to join NATO there's this short video that sums it up: https://www.youtube.com/watch?v=lWK_euAwrMk

Long story short: Sovereign countries got fed up with Genocide and aggression at the hands of Russians, who now believe that multipolarity is a rightful green card for unchecked coercion of neighboring countries.

If you want a deeper understanding I recommend the work of Stephen Kotkin, an actual Academic and Historian respected in academia and a reference all over the world (funny enough, even in Russia).