Ask the most ardent Trump or Obama defender (both of which hate North Korea), what exactly North Korea has done to the USA to warrant the possibility of war.
If you get any substantive answer at all, I would be shocked. In my digging into this situation, all I can find as the reason for the "hostile" relations between the USA and North Korea is that the USA is angry that North Korea is testing nuclear weapons.
Think about this for a moment.
Now I fully understand that North Korea is a communist government, but the reality is, so is the USA, we just don't like their brand of communism and prefer communism under the illusion of democracy.
So, anyhow, we are on the verge of war with North Korea because they dare to test nuclear weapons. This is the reason - there are no other reasons for war with them.
Perhaps you missed this story:
US successfully tests new nuclear gravity bomb
THINK ABOUT THIS