He is not crazy
Threats of Trump in the UN only reinforces the desire of North Korea and complete its nuclear program, as he knows that a country without nuclear weapons, it is easy to be invaded as happened in Iraq, Afghanistan or even Ukraine itself.
Nuclear bombs avoid wars, because countries know that it is destruction itself to attack a nuclear-armed country.
All countries that have nuclear bomb are stable countries, in addition to having seat in the council of security in the UN.
Thank you for reading.