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.

Even If Someone Else Already Stated The Obvious Re the Senate Briefing And North Korea...

I'll state the obvious: the only reason that someone would call a special briefing re the Senate and North Korea is that he or she wants to declare war on North Korea and at least appear to be legitimately doing so. When I first saw the news alert on Monday, I knew that that's what Tr**p was doing—after all, he has to look like he can get any honest vote, let alone honest votes from two thirds of the Senate. With the news of North Korea conducting drills, Russia being on the North Korean border, etc. (perhaps even including with the U.S. Navy Destroyer and an Iranian warship nearly edging each other—since North Korea and Iran are part of a political ménage-á-cinq with Russia, Venezuela, and pseudo-U.S.-ally China), now I and everyone else who's following the news has to know:

Tr**p is trying to set up a war for his own purposes, perhaps even colluding with North Korea—after all, "Birds of a feather...." 

Are There Really Seven Continents? Nope...

There are actually 10:

1. North America
2. Central and Caribbean America
3. South America
4. Europe
5. Russia and the Caucuses 
6. Asia
7. India and Indoasia
8. Australia and Oceania
9. The Middle East
10. Africa

Some example "Say what?" questions and responses to them follow:

1. Why 10 and not seven? 
2. What about Antarctica? 
3. Regarding Russia—really? Isn't Russia a country?

1. Even culturally, nuances between—for example—Central and South America, with Central America already separated from South America by being a part of North America, exist. On the other hand, clearer-cut distinctions between Central America and North America exists.
2. The North and South Poles technically are not continents—as goes for the Arctic, so goes for Antarctica.
3. With 21 republics alone, Russia—unlike with the United States with the 12 states that became more or less provinces or districts—is more or less its own continent that includes the state of Russia, just as Australia and Oceania includes the state of Australia.

From http://ontheworldmap.com/russia/administrative-divisions-map-of-russia.html.

Notes:

1. In political science, "state" means a government and the territory acquired thereby. Nation states include states of nations (Greek "ethnos", plural "ethni"): e.g., the classical and modern examples of Israel, Greece, and Italy (Roma, which later expanded as the Imperium Romanum that forcibly co-opted several nation states; and now is much-smaller Italy with Italic states such as Tuscany co-opted in it).
2. Holdout Rhode Island did not become the 13th state to ratify the Constitution until 1790!
3. For the Abrahamic religious groups, there has to be a total of 10 continents. See Daniel 7, focusing on Daniel 7:7-24. However one interprets Daniel 7, the fourth beast and the 11th king has to arise from Jerusalem (cf. Deuteronomy 32:8-10 and Ezekiel 5:5) be different from the other beasts and kings. In fact, even a Medieval schema looked like this with three kingdoms—with formal, informal, and hoped-for co-options—and Jerusalem in the middle: