> There is got to be plenty of counties who would be prepared to pay a lot of money for such a device, since it guarantees that they will never be attacked by t

> There is got to be plenty of counties who would be prepared to pay a lot of money for such a device, since it guarantees that they will never be attacked by the US. Not really. You need a device and a delivery mechanism. If either fail you are basically ending your country as an independent entity for the next couple of decades or so and you personally are unlikely to survive long after the failure. If you have one device and declare it the general public will not believe it (some will, those "in the know" probably will if they can confirm it, but most will think it is tin-hat BS) so you need two devices: one to "test" openly and one to hold in reserve. If you bought a device rather than built it yourself the game enters a cat-and-mouse phase where a large fraction of US resources will be devoted to finding your device and blowing it up, if they succeed then you die shortly after. If you get the device and just tell the US secretly that you have it then the cat-and-mouse game starts without the need for public posturing on either side and you (and most of the senior leadership of your country) are likely to find yourself on the unpleasant end of soft-power attempts at regime change and not-so-soft attempts that come from a busboy with a silencer. There is a somewhat fuzzy critical mass of devices and reliable delivery mechanisms that are required before you are a threat with enough credibility to use your nukes as a shield. NK probably has a few nukes, but their artillery along the DMZ and the proximity of same to Soeul is really the only thing keeping Kim Jong Il alive; your hypothetical country has almost no hope of hitting the US and if it is not close to a US ally that its people actually care about then all bets are off. If Sudan suddenly declared that it had bought a nuke then you could probably measure Bashir's future lifespan in weeks...