This article analyzes the US internal justification to invade Iraq in 2003 through a study of the ‘Bush Doctrine’ of 2002, several Congressional acts and resolutions on Iraq, and Presidential speeches before and during the mobilization of US forces. It argues that in order to find domestic support, regime change was one of the main goals, despite the references the US made to UN resolutions. Second, this paper uses Rawls’ ideas to analyze the US decision to democratize Iraq. The results of this study show how political philosophy can be used and abused to shape foreign policy. Rawls’ theory could have provided the US with a moral justification based on the liberal peace assumptions that were underlying their foreign policy. However, the US did not make a consistent appeal to those assumptions and acted like a Rawlsian ‘outlaw state’ instead. Therefore, this paper argues, the US lost the liberal justification to overthrow Saddam Hussein’s regime in favor of democracy.