They're playing "We actually do have missiles that can reach other countries. We are not powerless."
I don't think they want war. I think it's that they don't want the USA to try to colonize them like we did to the USA, Vietnam, the Middle-east, and a bunch of other places. The USA is known to be an incredibly aggressive nation that uses fear mongering and lies to get people to support war, when the war is really just a form of theft against other societies.
But really they got the US here, anybody takes any action against North Korea you are putting 35 million people who are living in Tokyo. almost 10 million who are living in Seoul.
I guess it's time to actually chill the fuck up and find a diplomatic solution or we are all fucked.