Published online by Cambridge University Press: 25 October 2016
Who supports multilateral treaties and who does not? We offer a systematic account of treaty ratification patterns paying particular attention to different states' roles in international legal cooperation in relation to the United States' ratification behavior. States' ability to influence the terms of treaties and their acceptance increases their incentives for treaty ratification. Multilateral powers—states that are powerful and independent from the United States—support multilateral legal cooperation because it offers them an opportunity to shape treaty content. Their engagement in multilateral treaties is strongest when the United States does not lead. States that are weak and/or dependent cannot greatly affect treaties and are therefore less supportive of them but are subject to US pressure. An empirical analysis of states' decisions to ratify prominent postwar multilateral treaties covering a wide range of global issues supports our argument.