Really? Cheap power doesn't lead to economic development? Are you developmentally disabled, or just a liberal?
"It is also naïve to think that the nuclear empowered nations do not take part nor have an interest on preventing that more countries develop nuclear technology."
Uh, duh. That's because those nations are led by warmongers who see non-nuclear armed nations as possessions rather than as free peoples. And they aren't far off the mark.
"I am not even thinking Iran, but Brazil and Argentina."
Yes, because US doctrine doesn't allow for South American countries that we can't topple at any time we want. You know, because the US is led by warmongers.