How does a buffer zone work against cruise missiles and fighter\bombers nailing your capital?
It doesn’t.
What a buffer zone does is delay your opponent’s armor and infantry from reaching goals inside your territory.
NATO doesn’t want to conquer Russia. Russia is to be held up as the perpetual bad guy who historically has been undefeatable.
Why? Military-industrial-government-globalist complex that wants to perpetually sell munitions and armaments. Removing the “bad guys” reduces what you can sell to the governments of NATO.
Is it too complicated for you and others to understand Putin’s very own words in that he does not want NATO next to Russia’s borders? Is it that difficult? Really?! His own words....