I think there is an unpublicized reason NK is being viewed as less than a threat.
Jong Un in probably chortling on a conference call with other world leaders over the domestic mayhem the US is experiencing at the further hands of Trump.
My guess is, "don't worry" America's enemies are saying to one another.  "Trump will let America implode just to keep his base happy."
"Plus, did you see that video on CNN where the White Supremacist hit the girl and then ran away?  Maybe we should be afraid if American Liberal Women wanted war, but that's not the case."