Today's North Korean regime embodies elements of both communism and Confucian dynasty, is sovereign with respect to only part of the divided Korean nation, is vulnerable to pressure from external powers, and confronts incipient internal demands for change, yielding an unusually broad set of possible transition paths and successor regimes. Such paths range from maintenance of the status quo to evolution, probably toward a more conventional form of military authoritarianism, to revolutionary upheaval, the latter in all likelihood implying the North's collapse and its absorption into the rival Southern state. This policy analysis quantitatively analyzes the probability of regime change and examines the character of possible successor regimes and the implications of these profoundly different trajectories for South Korea.