We examine the propensity of states to be involved in international conflict conditioned on three primary explanatory variables: percentage change in population over varying lags, democratic status of the state, and major power status of the state. Our aim is to have a better understanding of the effect of population growth on conflict involvement. We posit that the responsiveness of a government to the needs of its citizens is sufficiently important that the effect of population growth cannot be properly examined independently of democracy and that major powers tend to become involved in disputes for a much wider set of reasons than minor powers. Thus, we expect to find the strongest effect of population change on conflict participation and initiation in democratic minor powers. A series of Poisson and negative binomial regressions over 20 yearly time lags lends robust support to our expectations. However, contrary to what we anticipated, the effect of population growth on dispute participation and initiation in minor power democratic states is relatively rapid. Finally, when conflict is over the issue of territory, population growth has an impact on both participation and initiation for all types of regimes except major power democracies. This is most pronounced in the period after the end of World War I. We conclude with a discussion of the implications of our results.