Here is an interesting article looking at both the NK and the Iranian nuclear issue and our response/knowledge. Lots of long informative comments below the article.
http://www.commentarymagazine.com/2013/03/15/u-s-intelligence-north-korea-and-iran/
Conclusion ... more is known than can be indicated or is being indicated by leadership. Worried? If am correct the likelihood of space having been militarized has occurred and Americans are none the wiser.