@Mudge I must disagree: modern thought on EMP is that Starfish Prime was rather (well) overstated not to mention the difference between a MT-class warhead (Starfish Prime) vs. a low kT-class warhead (unboosted implosion).

Even an ICBM with low CEP would be sufficiently menacing. The range to Japan is barely IRBM-class and, again, CEP is not so dramatically important.

Choice of trajectory for the tests has been analysed in depth in academia (e.g. see http://www.armscontrolwonk.com/).

@cynicalsecurity I like armscontrilwonk's work. Additionally, I haven't seen any reports on efforts towards high gamma yield from NK but I acknowledge that media coverage in the topic is likely very opinionated in slant (and that they may not be going that direction at all).

Not sure what you're disagreeing with, as I was stating that I find it an interesting thought that I had not really considered before, but I do appreciate your comments and armscontrolwonk has some good work :)

@Mudge I am away from my library but will definitely find you the refs for the re-evaluation of the effects of Starfish Prime.

I find it particularly interesting because it goes from the "EMP scare" of the 60s to a more focused understanding of the effect on satellites (often seen as a probable conflict "opener" in a nuke exchange to blind the adversary) and the lack of effect on the modern telco infrastructure.