The Pyongyang regime’s survival strategy is intertwined with security challenges that the Republic of Korea and the United States (the R.O.K.-U.S.) military forces should overcome because the likelihood of the regime’s survival is, directly or indirectly, linked to changing and dynamic security interactions between North Korea and R.O.K.-U.S. alliance. The first security challenge, as it is linked to the most significant, actual threat, is the increase in the intensity and the frequency of provocations by North Korea. The second security challenge, as it is linked to the infrequent, but, potentially, most significant threat is the North Korean “contingency”: that is, the possible sudden collapse of the Pyongyang regime. Of course, we should not discount the possibility of full-scale war that can be considered the most foremost security challenge to the R.O.K.-U.S. forces. Also, we still need to consider the likelihood of the use of Weapons of Mass Destruction (W.M.D.s) by North Korea as an offensive option. Nevertheless, this paper argues that the possibilities of the second Korean War and the offensive use of W.M.D. capabilities are still low, although the likelihood of the limited scale of a North Korean attack is relatively high given the current mistrust and tension between the two Koreas. In order to effectively cope with the first and the second security challenges, this paper recommends the possible courses of action for the R.O.K.-U.S. forces.