“.....why would anyone use nukes???”
Remember Saddam Husain retreating when he thought all was lost and burning up his oil fields (the future) in the process?
Try backing a bear into a corner and all you have is bear spray. Any clue what will happen next?
Rational thinking can disappear in a heartbeat. That’s why the cold war lasted for 50 years (MAD). Our current leaders think MAD is something that happens to you when someone stands up to your foolish demands.
We are not backing a bear into a corner. The bear is planning on taking over the block.