The previous Kims used to do the same saber rattling about developing weapons but didn't actually follow through for the most part, or would offer concessions on what they had done in exchange for aid. The current Kim just keeps pushing forward with weapons development and the international community has not quite responded in kind to it yet.

Trump tried to reset relations with them (a worthy attempt I thought, even if I hate Trump) but it produced nothing. Biden hasn't really done anything about them (foreign policy for the US has been pretty distracted from NK lately).

What's the answer? More sanctions? Just let their people starve until they rebel or the nation collapses? I don't think there are any good answers. I suppose the best might be that China reigns them in somehow but I don't think even they have the pull necessary to do it.