If all existing nuclear weapon countries were to give up on their nuclear weapons, but not destroy them and instead hand them in to an international organization devised only for the need of containment against actors (be it state or not) that would potentially wish to develop nuclear weapons, would China be more likely to agree on participation in such an organization or not? What about other rising powers?
Uncle Ferd says dey gettin' ready to hit us with an EMP bomb... On land and sea, Chinas nuclear capability growing August 26, 2014 ~ Why is China, a country with a no first-use policy, upgrading its nuclear arsenal at a time when the United States and Russia are reducing their stockpiles?
I'd not worry about a Nuclear war or increasing stockpiles or capabilities - it would go against this http://en.wikipedia.org/wiki/Mutual_assured_destruction. No country with an ounce of belief in self-preservation would ever initiate anything.
