This article examines states' decisions to commit to human rights treaties. It argues that the effect of a treaty on a state--and hence the state's willingness to commit to it--is largely determined by the domestic enforcement of the treaty and the treaty's collateral consequences. These broad claims give rise to several specific predictions. For example, states with less democratic institutions will be no less likely to commit to human rights treaties if they have poor human rights records, because there is little prospect that the treaties will be enforced. Conversely, states with more democratic institutions will be less likely to commit to human rights treaties if they have poor human rights records--precisely because treaties are likely to lead to changes in behavior. These predictions are tested by examining the practices of more than 160 countries over several decades. (Contains 6 tables, 15 figures and 45 notes.)