Not surprisingly, the nations with nukes have not signed onto anything that would take away their deterrent factor, and, of course, Iran is hellbent on getting nukes for itself.
Not a single conflict since the United States dropped two A-bombs on Japan in 1945 to end a war the Japanese had started has used nuclear weapons. Rational people - even if they have nuclear weapons - know that using them is probably suicidal. Irrational people - like the Iranian ayatollahs - probably are the exception.
Alan Caruba blogs at factsnotfantasy.blogspot.com and is founder of the National Anxiety Center.