The article examines the relationship between women in society and the use of force by the state in the international arena. The arguments build on a conception of power relationships found in gender studies and feminist theories, and focus on how the internal distribution of political power at a societal level (as opposed to a state level) will influence the willingness of the ruling elite to engage in militarized interstate disputes and war. That is, the article explores the extent to which fertility rates directly and indirectly — through women’s employment and political office — are associated with the use of force by a state. The authors draw on public opinion literature, which shows that women's attitudes toward the use of force differ from those of men, to argue that the more women have access to the political process the more constrained will be the state in its use of force. The results of the analysis demonstrate that at the dyadic level, contiguous pairs of countries with low birthrates are less likely to go to war, while, more generally, the lower the birthrates the less likely is a country to become engaged in the more violent of militarized disputes. Our results suggest that policies to promote family planning might be one effective form of managing the amount of interstate violence.