I think you are reaching as far it is known, only China, Pakistan, India, Russian, Uzbekistan, Ukraine (the last three all part of the former Soviet Union), Great Britain, France, and Maybe Israel are the only ones on that list besides the U.S. that possess nuclear weapons. To say every country is really reaching as there are so many, many of them new, and many don't have the money or resources even if they wanted to possess or develope them. And if what you claim is true, North Korea would be the least of our worries, as many nations don't have stable governments or reasonable ones. Some of those many if they existed would you blackmail like North Korea tried to, to get more and favorable trade deals or free stuff from other nations. Others might have autocrats that hate each other and would thus resort to nuke wars. It is only by the example set in Japan that science and nations realized how truly powerful nukes were, otherwise we would have had a 3rd world war 50 years ago. But some autocracies show little concern for the own citizens let alone the world, so we would truly be in trouble.