Your point is well taken, DavidatMililani, however even so, the question Kim Jong Un must face is this: can he be sufficiently CERTAIN that our defenses will prove ineffective that he can push the launch button without fear of blowback from our surviving arsenal?

In this context I would respectfully observe Uncle Sam has had a very LONG history of weapon systems test and evaluation from which (thanks to those tests that “failed”) we have learned PLENTY. One doubts DPRK has had the resources to undertake such extensive RDT&E - - preferring instead to spend time and expense on public relations saber rattling to scare the West into more “negotiations” - - and the reliability of THEIR systems (e.g. under high thermal loads affecting warhead during re-entry, circular area probable at impact, &c.) may be very much in question even in THEIR minds.  After all they do not have anything close to our heavily instrumented missile range test facilities at Vandenburg, Kauai, or Kwajalein.