Not only is the Non proliferation treaty possible, it's been evidently effective in slowing the proliferation of nuclear weapons. The only country that ratified

Not only is the Non proliferation treaty possible, it's been evidently effective in slowing the proliferation of nuclear weapons. The only country that ratified or acceded to it and went on to develop nuclear weapons is North Korea, and the only country that ratified or acceded to it and looks on track to develop nuclear weapons is Iran. One country that was not a signatory and developed nuclear weapons voluntarily gave them up and acceded to it partly due to international pressure (South Africa). Israel, Pakistan and India have since developed nuclear weapons but they were never signatories, the only other non-signatory is South Sudan which probably won't acquire nuclear capabilities anytime soon.