Foreign policy determinants: Comparing realist and domestic-political models of foreign policy

Systemic realist arguments of foreign policy decision-making suggest that partisan disagreement stops at the water's edge. A domestic-politics model of foreign policy decision-making posits that politics does not stop at the water's edge. Extant research on foreign policy voting in the U.S. Congress is consistent with the systemic realist argument. According to this research, partisan voting is less likely to occur on national security, or high-politics issues, than on low-politics issues. I argue that this research suffers from two flaws. First, it does not measure high-politics in accordance with systemic realist thinking. Second, the goal in addressing the water's-edge question is not to learn if a specific variable, such as high-politics, is significant, but to compare competing models. To this end, it is necessary to engage in a '' three-cornered fight '' and conduct a nonnested model discrimination test. After creating a new measure of high-politics, I compare a systemic realist model against a domestic-politics model of foreign policy voting in the House of Representatives from 1953-2000. The model discrimination test indicates that the domestic-politics model outperforms the systemic realist model. Institutional dynamics and public opinion are more important for understanding foreign policy voting than are more traditional realist variables.