After all if they didnt do it then there would probably be alot of trade going on and people coming and going from Nkorea all the time and potentially exposing their population to new ideas.

The Kim clan's whole bases for keeping power is to keep all outside information from there people.

That means they is a practicle test, and will show they have advanced. The yield will say a lot.

My bet: They don't know how to do the initiator. Without that, all you get is a dirty conventional explosion. Bad, but not as bad as if the initiator works and supplies the requisite neutrons to begin the chain reaction. Without those neutrons, at the correct energy, there is no chain reaction before the whole assembly blows itself apart.

It's not an easy problem to solve, which is why it remains secret. This, for very good reason.

I know down here in South Korea we just got snow the other day. If the bombs are underground then it won't matter at all.

I have severe doubts about a UN resolution because of China. The story said China was in agreement, but I won't believe it until I see it.