> No NATO state will enter into this conflict, Putin has been pretty openly threatening with nuclear annihilation
This basically means 2 things:
1. NATO is dead.
2. Putin is free to do whatever he wants wherever he chooses.
NATO's mission has always been mutual defense of members. Ukraine is not a member.
The threat of Russian nuclear weapons has been more poignant in the past than today. Neither of your conclusions was true before.
We can see this security guarantee in action right now. Same will happen with NATO's mutual defense guarantee.
[0] https://www.npr.org/2022/02/21/1082124528/ukraine-russia-put...