Anyone around N.Korea should be VERY concerned. Not that they are gonna try to "nuke America", but that they are semi-capable if not fully capable of nuking S.Korea, Japan even maybe China.
But that brings up another issue, N.Korea is not gonna 'piss off' China, IMO this makes China the real 'threat' to The U.S. China has all but shouted to The U.S. "Don't mess with N.Korea(period)"...
Anyone who thinks that The U.S. should 'take action' against N.Korea is either ignorant as F, or crazy as F, or both. Unfortunately, there are SO MANY westerners that are ignorant loons, especially on such issues as politics and war