I remember a day when we the USA had a no tolerance mind set towards power hungry countries like N.Korea. Do you think we would have the same actions towards N.Korea if their country was relocated to say where Hawaii is? I guess the mind set of this new administration is too put the threat off until it becomes so real that we can't ignore it or maybe until Japan has a third radioactive wasteland smack in the heart of Tokyo.
N.Korea reminds me of the bully you take abuse from until you give them one straight right to the eye and it corrects their thinking. Pressuring China to get involved is that straight right to the eye.