This study examines the interaction between the pro-democratic movement and the authoritarian military regime of South Korea in the 1980s. Contemporary democracy research is dominated by two opposing theoretical views: Voluntarist approaches tend to conceive the transition from authoritarian rule to democracy as a negotiated process. Structural approaches view the transition to democracy more or less as an outcome of structural conditions, in particular the balance of power between incumbents and challengers of a regime. We consider both perspectives not as competing alternatives but rather as accounts of two different structural dynamics: In some stages of the democratization process, it is more appropriate to interpret the confrontation between pro-democratic challengers and power holders as a (structurally determined) non-cooperative game. In other situations, both sides may recognize that cooperation (and negotiation) leads to a better outcome than a pure strategy of confrontation. The analysis focusses on the interplay between the two structural dynamics on the empirical case of South Korea in the 1980s. A process tracing analysis highlights three critical junctures in which the democratization process shifted from sequences of non-cooperation to sequences of cooperation and back. On this basis, we develop an analytical process model that integrates the two (opposing) theoretical approaches on the temporal dimension.