The most clear example of a possible solution was Albert Einstein's proposal for a United Nations 'with teeth'.
The majority of the worlds super powers were not happy about this because of course it would mean they too would have to play ball and give up their toys 'or else'. What didn't work on a global scale most likely would work on a smaller scale if the superpowers that remain could agree on any of this but so far even Kim and his bomb seem to not be enough to tip the scales.
Trump being regarded as unstable and untrustworthy by the vast majority of the rest of the world doesn't help either, there is an outside chance that with some cooler heads in the White House that a deal could have been made. As it is just about every other government / head of state has been insulted in one way or another and Kim seems to be mainly aiming his aggression at the United States so for the time being this is a stale-mate. And I really hope it will continue to be a stale mate.
All the other options (assassination of the Dear Leader, limited war) other than sanctions seem to be off the table for now, and even the sanctions might be rolled back for simple humanitarian reasons and because they are not achieving what they are meant to achieve.
The very long term future has only two possible outcomes as far as I can see: either we will have a world government, for good or for bad, or we will end up destroying a good chunk of the planet in World War III triggered by some idiot because nuclear weapons will become more and more available until even the most unstable regimes have them. And NK, even if it is pretty bad and obviously led by a megalomaniac, is not as bad as it gets. Pakistan and India are another potential area of trouble.
The nuclear genie will not go back into the bottle, our only option is to try to contain it in a way that strikes large and small countries equally, anything less will not do and will only result in carnage down the road.
The people that point at the mutual destruction guarantee as the thing that kept the world 'safe' for the last 70 years miss the point that 70 years is absolutely nothing on the timescale of the human race, it is a single human life-span and there is absolutely no way that you can extrapolate from that 70 years to the 1000's of years that this would have to hold true for it to really work. Too many 'close calls' for comfort during those 70 years, every single one of those could easily have led to a huge disaster.
So until China, America, Russia, France, the UK, Israel, Pakistan and India are ready to give up their toys you can expect the small fry to continue to want to have theirs too.