This paper examines the three US national security strategies released by Presidents George W. Bush and Barack Obama since 9/11. These national security strategies are required presidential statements describing US plans for national security. The authors analyze Bush's two and Obama's one post-9/11 national security strategies and evaluate the argumentative framework of imperial righteousness in the documents. The rhetoric of American imperial righteousness contains four themes: national security, the nature of the enemy, freedom and democracy, and American morality. While there are some differences between the documents, the authors argue that Bush and Obama both promoted the idea of imperial righteousness in their plans for American national security. Moreover, the four themes of imperial righteousness worked together effectively to advance America's interests in world affairs.