Ok, maybe one was a bit of an exaggeration.
I should have said "All it takes is one deranged individual and a handful of his his hand picked sycophants."
I think it's not a matter of if, but when. All it takes is one deranged individual.
The only way to disarm the world of nukes is to unite under a rational, evidence and incentives based, benevolent world government. There's literally no other way to get rid of nukes if you've studied it.
Even if every nation disarms they all live under the threat of another building them in secret. As soon as one of them suspects as much the race is back on to re-arm.