That letter Trump dictated might as well have been written in crayon. Completely bizzare and barely articulate.
Trump is the only American president in history that could make Kim Jong look even remotely reasonable.
If this was part of a North Korean plot to discredit America, divide us from our allies, and give of a whiff of perception that NoKo was being reasonable and seeking diplomatic solutions, the scheme played out almost to perfection. NoKo can plausibly claim they tried diplomacy, but in the view of Trump's threat to wipe them out and kill their leaders (Bolton's Libya model) - they might feel they can plausibly claim they have a right and a need for nukes.
In short, our Orange Pig may have gotten his ass handed to him.