[igravious]

Proximity to the Russia heartland presumably. Flight time of missiles to key military positions within Russia.

I'm no military strategist but how is this not obvious?

It's not about a neutral zone, it's about a buffer zone between more sensitive areas and where NATO can place troops, tanks, and missile systems. I mean a sea separates Alaska from north-east Russia and those places are deep into permafrost territory and then there's the entirety of Western and Central Russia between Moscow (say) and there. Russia is huge. 90% of the Russian population live in the 10% of Russia that is considered part of the European continent.

It's like nobody bothers to study geography or geopolitics before they open their mouth these days.