When was their last nuke or missile test?
Most of what's happening is because NK's done, finished, finis ... with those test site tunnels. There was an accident? and some length of tunnel collapsed. They were ripe for abandonment anyway.
NK has taken the rocket and bomb tec they got from the Pakistanis and Clinton and developed a rocket capable of reaching most cities on the American mainland.
We
must assume they have reduced warhead size to fit those rockets, and so NK can deliver a nuke into the American heartland.
We know they have 10 to 12 warheads.
Destroying already seriously damages test site tunnels has not reduced their nuclear warmaking capability one iota. Their rockets and warheads are, of course, in no way as refined as they might be, but they are fully adequate for warmaking.
Kim Jong Un has no less nuclear capability at his disposal than he ever did. Nor do we really know, through the years, how much weapons grade uranium NK has produced and stockpiled. They could possibly, without anymore actual bomb testing, build many more warheads.
So rocket boy comes to the table with flush with power.
What will happen?