Apparently it can reach anywhere in the world.
What is the next move?
Blockaid anything and everything to and North Korea.
Anywhere in the world? Maybe if they ship it fed ex but I doubt it would find much if they tried launching one. I bet it would be like one of those 4th of July skyrockets that go up about twenty feet then start spinning around and chases everyone then blows up under a lawn chair.
Attack. The country doesn’t have it anymore though
Sadly, the next move is the obvious one. We preempt strike them. Hope for minimal civilian losses.
What's the payload? Even a miniature nuke is pretty heavy. They have not shown that they have a device that can withstand reentry shock.
They do not have a credible nuclear weapon, but they are certainly well on the way. Only one country has ever done an end-to-end test of a nuclear device, from launch (from a submarine) to detonation over land.
We go along with the fiction that this isn’t China threatening us.