Instead of the Ukraine having joined NATO,
NATO has joined into the Ukraine.
Now, were NATO to pull out of the Ukraine, then it would be admitting to a quick and easy defeat of NATO by a Russian expeditionary force.
This spells the end of NATO, thus even pretend-neutral countries like Sweden and Finland join with the weaker party (NATO) in order to maintain the balance of powers across Europe. This balance of powers is also in the sense of keeping the Feudal-cast in Western Europe in the role of a lord-protector outwardly and abuser inwardly.
This class-system would wither, fall and perish before Russian supremacy.
https://www.veteranstoday.com/2022/05/21/us-drawing-up-plans-to-sink-the-russian-black-sea-fleet-ukrainian-official/