Also, keep in mind almost all of NK's artillery is cold-war era shit that's hardly maintained, manned by soldiers who are malnourished and undertrained, and could be absolutely carpet bombed to hell before they could even react.

North Korea has one of theach largest stockpiles of VX nerve agent among a plethora of other chemical weapons including Sarin and Mustard gas that are far more devastating that you might think. Any conflict with NK would immediately Hundreds of if not thousands of chemical weapons launched directly at South Korea specifically Seoul potentially killing 100's of thousands if not millions, the population of Seoul is roughly 50 million people and their only 35 miles from the border...let that sink in. VX is no joke...it will kill you within minutes and they have tons! You only need a few tenths of a milligram to kill a person. https://en.m.wikipedia.org/wiki/VX_(nerve_agent)

This is just one of many disturbing reasons why we want to avoid military conflict with NK at all costs.