(Guam is a USA military base necessary to maintain wartime operations so far from the California coast, it was critical during WWII)
only good news is North Korea is stating this intent FORWARD rather than keeping it secret. we'll be waiting to see if they make a schedule that runs without any endangerment to Japan and Guam, if such a test can even be done from land to sea (ie, rather than from sea to sea on a totally different gps coord)