where's it coming from

I'm just a little curious how is it that all of a sudden N. Korea, iran, anymore? are capable of nuclear weapons? with all the different countries that I'm sure have been watching them for the past what 50 years? Governments watching as most citizens don't know the country exsist till the government starts bombing it. But I'm just a little curious if they all teamed up together to make them if they all bought them somewhere or what? I mean I do beleive that people can figure it out on their own but so many so close together time wise that is. any thoughts?

p.s. not sure if this is politics or conspiracy so i guessed