Successful entrepreneurship is ultimately a matter of flair. But there is also a fund of practical knowledge to be acquired and, of course, the right legal and financial framework has to be provided for productive enterprise to develop.
North Korea desperately needed the foreign currency which this lethal trade could bring; its role as chief 'rogue' reinforced its prestige among anti-Western states, near and far; and it could also hope at the right moment to extort new instalments of Danegeld from America and her allies.
For my part, I favour an approach to statecraft that embraces principles, as long as it is not stifled by them; and I prefer such principles to be accompanied by steel along with good intentions.
The habit of ubiquitous interventionism, combining pinprick strikes by precision weapons with pious invocations of high principle, would lead us into endless difficulties. Interventions must be limited in number and overwhelming in their impact.
A world without nuclear weapons would be less stable and more dangerous for all of us.
We must try to find ways to starve the terrorist and the hijacker of the oxygen of publicity on which they depend.