I’ve dealt with Koreans at many levels, military and business, enough to get behind their facade to get to understand that they think differently.
They are an insular people and consider themselves superior to all other peoples. If you are their friend, or useful to them in some way, you can’t do better. If you or those you affiliate have oppressed one of them in any way, they are a permanent enemy, to the death.
They consider fair and honorable, any agreement that can be negotiated today, in the moment. Whatever was agreed to, at whatever cost or value, previously, is irrelevant.
They hate, in this order: Japan, China, and lastly, all Western Powers (equally).
They will never peacefully give up any weapon, nuclear, missiles, or otherwise.
Some years ago, due to blight and crop failure, about 10% of NK starved to death.... They did not complain or beg. In fact, the bags of rice that we gave them, labeled “From America”, they spray painted on another word above in Korean that said “Tribute”.
Our threats are nothing to them.
That is what the Japanese people believed up until the end of WW2 and the introduction of the A-bomb.
These things can be cured but it takes a generational shift