The level of female representation has been found to lead to lower military spending and a lower level of state aggression. However, I argue that previous work has largely overlooked the impact of the international system on these three domestic characteristics. Specifically, the presence of an external threat from an interstate rival increases military spending, increases state aggression, and lowers female representation. Tests of this theory on democratic states from the years 1981 to 2007 find that the level of female representation decreases in states involved in an interstate rivalry and has a greater effect on female representation than factors routinely found to influence female representation. This article brings the international system into the discussion of factors that influence female representation while adding to previous literature on how the international system influences domestic politics.