It has been popular belief that NK has had nukes for years. This just confirms it. I suspect Japan had already been planning on a nuke program.
There are few things we can do about this except work towards an internal coup but even then we have to worry about ensuring relative stability as we don't want complete chaos to ensue and terrorists getting the nukes. Dicey situation. It's not like Pres Bush can just push some button and fix this. Sorry. You will just have to deal with this I'm afraid. I've dealt with this since the 50s.
"I suspect Japan had already been planning on a nuke program."
I cannot help but think they have a program separated by 'chinese walls' which only requires minimal assembly to be a completed nuke.