OK, I understand.
As mentioned by others, the nuclear "cat is out of the bag". It is only time before nuclear weapons will be used again. We can only hope to postpone these events. Along the way, we will make both correct and incorrect steps. Nobody can tell the future and nobody can rely fully upon covert intelligence. Pakistan can turn radical and we have a real problem. Iran, which contains one of the youngest and best educated population in that region, may change governments and not be a threat. At that point we could not make a case for preventing them from having nuclear weapons.
As mentioned by others, the nuclear "cat is out of the bag". It is only time before nuclear weapons will be used again. We can only hope to postpone these events. Along the way, we will make both correct and incorrect steps. Nobody can tell the future and nobody can rely fully upon covert intelligence. Pakistan can turn radical and we have a real problem. Iran, which contains one of the youngest and best educated population in that region, may change governments and not be a threat. At that point we could not make a case for preventing them from having nuclear weapons.