For a few brief years after 9/11, the U.S. Supreme Court reined in the executive branch’s most sweeping assertions of wartime power, upholding the constitutional rights of military detainees. Then the Court decided it had gone far enough. Even as the “war on terror” grew beyond spatial and temporal limits—becoming a global set of military interventions with no apparent end point—the Court regularly ruled that judges should defer to the government when it invoked national security. In cases involving everything from surveillance to immigration roundups to the “Muslim ban,” the Supreme Court asserted that courts have limited authority and expertise to review the government’s actions, even when there is no alternative means to hold government accountable for misconduct. These decisions reflect the Court’s larger agenda of expanding presidential power and empowering law enforcement and security agencies, while weakening the state’s capacity to regulate in the interest of public health, welfare, and the environment. Within and beyond “national security” contexts, attempts to insulate the carceral state from accountability draw on perceptions of nonwhite communities as threats to safety and national identity. As the second Trump administration expands the war on terror to target a still wider set of perceived foreign and domestic enemies, the same Court that has unshackled the executive will decide whether to constrain the new administration’s increasingly authoritarian and lawless policies.