Kim warns troops to prepare for 'sacred war': Should the US support South Korea?

[pennylane100]

17. The US has quite a few troops in South Korea

While their presence is a deterrent to North Korea's dreams of invading South Korea, it is possibly (I am no expert) just as beneficial for both countries. There may be some strategical value to having a US presence in the area. If so, it would seem most likely that any treaty signed would include mutual aid against acts of aggression.
Of course, in this case, the aid will mostly be provided by the US. However, it would almost be impossible for the US to ignore an unprovoked attack on a country this is currently hosting US soldiers.