I feel he will still be a strong leader even after he completely eliminates his nuclear arsenal. He has destroyed major architecture which was part of his nuclear capabilities such as testing facilities.
Donald Trump knew or was advised that Kim Jong Un enjoyed negotiations I feel. He doesn’t necessarily take on a standoffish position just because of it being nuclear talk or any other topic such as world trade.
Denuclearizing of any country that decides to deal with the US on terms of its own does show many things to the world. One thing Kim Jong Un is showing now would be more strength in the face of might such as when swords or spears with bravery were the only defense.
One other thing being shown to the world is the US may not necessarily need to be feared after verbal, or military conflict is resolved. I hope one day that the answers needed to solve the war on terror could be that nice. Friendly nations trade together such as through Free Trade agreements.
The US is giving lessons to other countries often such as what conflicts need war or good diplomacy. I liked cold war era spy thrillers where the US was in just as coldly as the other side. It may not have actually been that way except for seeing LBJ or Kennedy stand up to aggression.
For a few weeks I had bouts of fear which I related to others over the drama which was unfolding in the Korean Peninsula. Now I see two leaders hugging each other with friendly embraces and smiles being present. Both sovereign Korean countries have superpowers which still continue to trade supporting them in the background.
In any violent situation where two people who know each other need to return to being close or to at least end the violence the rule is for the one who is most brave not to hit back. Sometimes letting go of an issue and walking away is the only terms to end an argument. Tae Kwon Do teaches tenets like that to its students of the Olympic sport.