Entirely different scenario and dynamics. IF the Red Chinese did not intervene as they did in December 1950, then the DPRK's economy and military would quickly disintegrate and collapse under the weight of a combined ROK and US counterattack, which has been wargamed and planned ad nauseum ever since the mid-1990s. Any war would be over in a few weeks, IF the Red Chinese stayed out of it and IF Obama actually had the will and backbone to prosecute it to victory.
Big 'ifs,' admittedly.