None of North Korea’s neighbors want to see the collapse of its repressive regime, whatever they say in public. That’s the dirty secret behind all the diplomacy surrounding the current crisis. The last thing China wants is a unified, pro-western Korean nation on its doorstep — with US troops stationed on the other side of the Yalu River on its border. That’s a prospect Mao Zedong went to war to prevent 67 years ago, when China was far weaker than it is today.

They would never dare say it but Japan too is wary of a strong, united Korea, given the long history of distrust and destruction between the two.

Even the South Koreans baulk at the idea of spending vast sums bringing their impoverished cousins into the 21st century. It’s only the poor North Koreans themselves, half of whom live in extreme poverty, and all of whom exist in a climate of fear and servitude, who would benefit from the fall of the socialist dictatorship founded by Kim Il Sung in the 1940s.

That is why the world is so frustrated by the unpredictable and potentially genocidal behavior of his grandson Kim Jong-un.

If the tyrant was happy to stay behind his barbed-wire borders and only threaten his own people, the world would leave him alone.

But his ballistic missile launches and nuclear bomb tests, and the development of the technology to put the two together in an intercontinental weapon that could hit the west coast of the U.S., makes that impossible.

Portrayed as the wild-eyed aggressor, Kim Jong Un is really acting defensively. Like his father and grandfather before him, he sees the acquisition of this 70-year-old technology as the key to his survival and that of his family’s empire — noting the fate of Colonel Gaddafi and Saddam Hussein when they failed to develop deliverable nuclear weapons.

The key to solving the crisis is to persuade him that far from securing his regime this will bring about his downfall. That won’t be easy, but is possible. The deal with Iran to pause its weapons program is the model. That would enable the rest of world to leave North Korea alone, and avoid the question of what would happen if it no longer existed.