Nuclear weapons deliver strategic heft in a world of fierce competition. They are a deterrent against attack by another country and a symbol of national power, bringing status and - perhaps most crucially - global attention. In this, nuclear arms are a weapon of mass persuasion. Or perhaps more often, intimidation.
If the Stalinist North Korea had not developed the bomb, would the West have devoted so much sustained attention to this reclusive country? Pyongyang has not carried out a major attack on South Korea in more than 50 years - despite the two countries remaining formally at war.
Yet it was the spectre of nuclear weapons that gave North Korea a critical bargaining chip - first, coyly to play along with negotiations to stop its nuclear program and not share the technology, and now, in on-and-off talks about abandoning the bomb. All the negotiations are predicated on an exchange in return for international support. The regime gets all the attention it wants.
Recognising that nuclear weapons are most often tools of persuasion is a good part of the reason why some international commentators - a few high-profile US conservatives especially - call for abandoning engagement with North Korea and allowing the regime to collapse.
The counterpoint is to raise fears of what a desperate North Korea might do with its existing nukes and technological skills. But that risk, it is argued, can be mitigated by close inspections and sanctions.
In a provocative new book, Atomic Obsession, Ohio State University professor John Mueller argues that the fear of nuclear weapons is too often overstated, distorting the response.
''The world has managed to live for two-thirds of a century with increasing numbers of nuclear weapons, now amounting to tens of thousands dispersed over several countries. Plenty have existed, but none have gone off. The notion that they automatically will somehow explode or cause major trouble could now use, one might think, some re-examination rather than empty, if alarming, repetition,'' Mueller writes.