Scholars have long debated whether and how international law impacts governmental behavior, even in the absence of coercive sanction. But this literature does not sufficiently address the possible impact of international law in the area of national security policymaking. Yet, policies that the executive branch purports to adopt as a wholly discretionary matter may still be heavily influenced by international legal norms, regardless of whether or not those norms are formally recognized as legally binding. And those policies can be surprisingly resilient, even in subsequent administrations. Moreover, because they are only seen as discretionary policies, they may be more easily adopted than formal legal interpretations. For all of these reasons, the impact of international law on national security policymaking is a crucial unexplored area in the debate about the efficacy of international law.

This Article describes how the norms and values embedded in international human rights law can sometimes be adopted, if not as a matter of formal law at the international level, then as a matter of official policy and practice. In addition, it surveys the advantages and disadvantages of such an approach, using two different Obama administration counterterrorism policies and Trump administration successor policies as case studies. Ultimately, I argue that the emergence and persistence of such policies is evidence of international law’s constraining impact. International law, it turns out, casts a long shadow as its paradigms get translated into policy. I also analyze the attributes of these policies, including their “legalistic” character and the consequences of creating policies of this type. This analysis suggests that importing international law paradigms into national security policymaking can be a pragmatic and effective alternative to formal international lawmaking, though it also may side-step the process of creating robust new international law rules. Therefore, it is a practice that executive branch officials from the United States and other countries, human rights organizations, and administrative, constitutional, and international law scholars should at least consider, while weighing both the pros and cons. In addition, the stickiness of such policymaking, even across administrations, illustrates the importance of institutional path dependence, the role of lawyers, the constraint of interoperability with key U.S. allies in multilateral military actions, and the way norms get embedded in government organizations.