Kiev is 529 mi (~10h) from Moscow. If Ukraine were to join NATO, there would be a NATO base inside that range in days. Lockheed Martin claims its Precision Strike Missile has a 310 mile range [1]. I can understand why Putin would want Ukraine to be a friendly puppet or be demilitarized.
Diplomatically, it wouldn't be advisable to give an adversarial foreign power control over the membership of your alliance, so NATO can never give those guarantees. My belief is that Putin only sought those guarantees to fabricate a casus belli.
I think you forgot your own argument. Let me remind you: "If Ukraine were to join NATO, there would be a NATO base inside that range [529 mi] in days."
You are trying to justify Putin's actions by inventing a hypothetical while ignoring the fact that the NATO borders within 500 miles of Moscow is a reality for years.
Sure but the US and NATO had no interest in doing anything like that. Nobody gives a crap about Russia as an enemy except to the extent that they make themselves an enemy.
NATO alliance members have NATO military bases, but you're right that US and NATO have no interest in adding Ukraine as a member. As we are seeing, the country is in a weak geographic position: Russia was able to stage forces to encircle >80% of the country prior to the invasion. Who would want that kind of ally?
Diplomatically, it wouldn't be advisable to give an adversarial foreign power control over the membership of your alliance, so NATO can never give those guarantees. My belief is that Putin only sought those guarantees to fabricate a casus belli.
[1] https://www.lockheedmartin.com/en-us/products/precision-stri...