I suspect this originally started as posturing. But I think we are past that point. The only thing we can hope is that if he does launch an attack, it either fails spectacularly or takes a minimum of human life.
A personal pet theory I have is that as soon as NK launches an attack, China invades and annexes the country. South Korea would probably make a huge stink about it, but I think the EU and America would breath collective sighs of relief at it not being their problem. NK has apparently been sitting on a lot of natural resources for years that they can't really do anything with, not to mention a relatively docile people who are already accustomed to treating the Chinese as allies. What might take decades of work for other countries could take a few years for China.
While it would suck for the NK people to go from one communist regime with no respect for human life to another, I don't know what kind of alternatives there would be. I think the reason we haven't seen war so far already is how much of a fucking nightmare it would be to get involved in a conflict with them. It's easy to write off the North Koreans as backwards dirt farmers, but they have one of the largest (if not the largest) standing armies in the world. They have nearly two thousand tanks on par with the Abrams and have spent years preparing for a ground war on their own soil. A ground war with them would be a fucking nightmare, their countryside is bristling with anti-air batteries, and I don't think anyone wants to nuke them.
Just as a minor point, I do think that the NK military won't be nearly as useful as it looks on paper.
Of course a non-zero number of those tanks and artillery pieces and missile batteries will actually fire when their triggers are pressed, and some of those may even hit their marks, but how many is a big goddamned question mark. Also, unless China decides to support them outright in a war, they'll be starving in the dark with no gas in a week. And if China DOES support them, then we've all got way way bigger problems.
Also, FWIW, the Chinese may have massive issues as a repressive state, but a Chinese bootheel would be fucking Candyland compared to what they've got now.
I still say the best possible solution is for NK, China, Japan, and the US to all sit down together - in secret if need be - thrash out a "desired outcome" that everyone can agree with, then and get a plan in place to manipulate, prod, or outright shove NK there. Is that likely? No. But now that China is getting more and more freaked out by the lunatic living in their backyard shed, it's no longer impossible. The motivation is there among all parties. If China can be soothed, real progress might actually be possible.