Despite the superiority of the ROK Army in weapons and aircraft, they will be atomized. The North Koreans have two assets; nukes and an outstanding infantry arm. If US Army counterattacks, keep an eye to the Yalu. In a non nuclear confrontation the ROK would obliterate the North. But the North, commanded by a dictator who is clearly psychopathic, is going to use all of his nukes at the same time and level out the playing field.