Let Japan and South Korea Fight Back Against North Korea, Because...

1. Japan and South Korea are the main countries in harm's way because of North Korea and China. Besides, the U.S. Armed Forces are overstretched as is.
2. Aspiring dictator Tr**p is allied with China and has praised Kim Jong-Un, and Tr**p is also allied with Russia. Besides, as I've said before, Tr**p plays nobody's puppet. Thus, Tr**p is trying to cover his own trail with his bluster and put the United States along with Japan and South Korea in harm's way. 
3. Tr**p is, at the least, no different than Kim Jong-Un, anyway; and, at the most, worse than Kim-Jong Un—do I or others need to rehash that Tr**p, e.g., keeps a copy of ******'s speeches by his bedside?
4. Given Tr**p's White Supremacist attitude and Guam's Non-White majority (and don't think that Tr**p doesn't know about that), Tr**p's at the very least not going to care if the mostly-Chamorro Guamanian population gets hit by North Korea. Also, Guam is a United States territory as opposed to a United States state. 

There are other reasons as well. Nonetheless, the four aforementioned reasons are sufficient-enough-to-mention reasons. By the way and as I have to reiterate, don't think that Tr**p doesn't know about Guam's demographics—anyone can look up Guam's demographic information in the "CIA World Factbook", and a racist and so-called "POTUS" like Tr**p would know about that as "POTUS". In other words, don't be fooled by someone as bigoted, narcissistic, and sociopathic (e.g., maliciously-shrewd and -calculative) as Tr**p wherein Guam is concerned or in any other case.