Ah! Here you are. Getting back to our "informal" doctrine of preemption. I am of the opinion that the merely an attempt to construct WMD should be the trigger. Especially of the country attemption to construct such weapons is a communist country, with a history of human rights violations, with whom you have a negotiated cease fire.
If the US continues to allow rogue nations to join the "nuclear club" it only be a short matter of time before an accidental or intentional nuclear detonation occurs.