Seems like most folks here believe 1. KJU is rational and would not jeopardize his regime. 2. KJU would not target the USA (see #1). 3. The US would move US persons from the Korean peninsula before any kinetic military action, nuke or otherwise. and that 4. The USA would respond to an attack with devastation.
If KJU is rational, there is still no guarantee that those surrounding him are. It is highly likely in a dictatorship built on a cult of personality that established nuclear safeguards are not SOP. The chances of an accidental or unauthorized attack is much higher in the sort of environment that exists in North Korea. Will it make any difference if the attack is not belligerent? I think it just may. Would it be rational for KJU to use his nukes to degrade a perceived threat and then pass it off as accidental or unauthorized expecting the USA not to respond or in a manner he can survive?
A rational KJU would see any effort to move US persons from the peninsula as a precursor to an attack. As a minimum, a huge escalation. Moving US persons would increase the likelihood of a preemptive attack from NK. The folks living in South Korea are canon fodder. There have been very serious conflicts since the 1950s. Never has an evacuation come close to being ordered. I would not rely on the American government evacuating to prevent American casualties.
We are talking pretty tough. But acting proportionally is a default setting for America. North Korea has played the West for decades. They always get something in return for their seemingly irrational or otherwise bellicose actions. So lets ask ourselves this. How much are we willing to pay? Just how far are we willing to go when North Korea extorts the West with nukes in it's quiver? Wheat, no problem. Oil and coal, sure. Disputed territory, ...maybe. Military technology and weapons transfers from China, ...hum? There must be a limit, where is it? We have already let Russia roll over more than one country. Why wouldn't KJU think he can get away with the same when he has nukes?