Guam is arguably solely used as a military base for the USA and about as pure a military target as one could possibly hope for as a target.
It would suck to be a native there, but they have only themselves to blame for neither repelling the USA through strength or arms, or demanding to be a full USA state (with all the benefits, like getting $60,590 a year as a USA/Hawaii welfare recipient) instead of just a "slave" state as a territory.
I don't think Kim Jong could get away with nuking Hawaii (full state status) And its also pretty damn easy to just sail a nuke in at 5 miles per hour, on one of his submarines if an ICBM should miss such a small target. Arguably Hawaii would be just as easy to nuke as Guam, as again - if you miss with the ICBM, just sail one in mixed in with the dolphins (no nuclear miniaturization needed)
Arguably, both Hawaii and Guam were used as forward operating bases when the USA bombed both Korea and Vietnam for one million and two million civilian losses respectively. I would not be surprised at all if Kim Jong has already planted a nuke on the beach of both islands as a backup on ICBM miss.
Does beg the question: Should the US apologize for killing off people in countries nowhere near their soil?