Post-World War II Western foreign policies are often based on the claim that the spread of democracy will result in global peace. Our understanding of how this propagation can bring about peace is limited, and we have little reason to believe that the causal arrow points only in one direction. We tackle these issues by modeling the linkages between states' regime types, interstate conflict, and the strength of the democratic community relative to the autocratic community. Analysis of our model suggests initial increases in the strength of the democratic community increase the level of conflict in a system. Beyond a threshold of democratic strength, however, conflict wanes as the democratic community waxes. Our model also suggests that the survival rate of democracies increases as the material strength of the democratic community increases and decreases as systemic conflict rises. Empirical analyses offer support for the survival propositions.