The United States has been reluctant to agree to binding international human rights instruments ever since the very first meeting of the United Nations Commission on Human Rights in 1947. This article explores structural causes for that reluctance. Internal government papers show that US government officers worried that a human rights treaty might expand federal jurisdiction at the expense of the jurisdiction of the United States' constituent states and could provide an opening for judicial activism by the courts. These concerns made domestic political sensitivities more acute and raised principled questions about the desirability of pushing domestic reforms through international law-making. US representatives made repeated efforts to ensure that an international bill of rights was drafted as an aspirational declaration rather than a legally binding treaty. They also proposed clauses designed to delay or limit the domestic effects of any agreement, while reassuring the US Senate that domestic power balanc...