You are running the US. N. Korea now has a nuke. What would you do?
Do we stop them? Attack, diplomacy, what? Ignore it? What if S. Korea and Japan ask us to help? Do we risk bein called imperialsts if we attack, or do we just hope it goes away?
You know, if we attack or otherwise try to stop them, we may increase the risk of retaliatory terrorism, and worldwide opinion of us may go down. Maybe we should send them flowers and hope they go away?