So you think about what does this mean? First, it means that the missile lobbing contests of North Korea and the US are really a side-show. The US cannot and will not invade or bomb North Korea for many reasons. One of the most potent reasons is the massive loss of life, even if restricted to conventional weapons. Seoul's megacity of 12,000,000 is within easy striking range of standard artillery as well as short range missiles. There is no effective defense of Seoul possible.