One thing is scary: North Korea is making unusually bellicose threats, even for that country. If it does nothing right now, then the threats become meaningless quickly.
There are various YouTube videos which analyze the recovery time (months) if a large area of the country were hit by an EMP high altitude blast, even launched from a ship. The conceptual problem is that a rogue state (North Korea, Iran) or asymmetric group, possibly acting in mercenary fashion from a rogue state, could possibly make repeated attacks, keeping much of the world under subjugation. People who had grown up "spoiled" (as some of the less developed world sees it) by technology could wind up living the last decades of their lives (if they survived at all) under primitive and authoritarian conditions. This grim possibility should not be taken lightly. The world hasn't seen a situation quite like this in modern times (Hitler makes a comparison of course, but so do some of the exiles and conquests in the late Old Testament years). No civilization should take its personal freedoms for granted. One cannot afford to be smug, or insular. One should not hide in indifference.
I suppose I could boast, "I told you so." I surely hope not.