Treaty-Making and Partisan Politics: Arms Control and the U.S. Senate, 1960-2001

Because the impact of domestic politics and institutions is increasingly important to understanding foreign policy, the motivations and interests of individual members of Congress are even more important for understanding American foreign policy. Contrasting the well-known thesis that “politics stops at the water's edge” with a “politics past the edge” thesis, we examine an issue arena typically considered immune from the intrusion of domestic politics. Set against the context of previous studies concluding that partisanship exerts a growing impact of congressional behavior in foreign policy, this paper extends current studies to examine the impact of partisanship and other variables on Senate voting on arms control treaties on weapons of mass destruction. With a data set of votes that spans the 1960–2001 period, we employ logit regression to gauge the relative importance of three determinants of congressional voting emphasized in theory and roll call vote analyses—partisanship, ideology, and electoral concerns—while also controlling for a variety of other factors. Our results indicate that partisanship becomes an increasingly important factor in Senate votes on arms control treaties in the post-Vietnam and post-Cold War eras.