Charting a course through US administrations from the late 1990s to the present day, this article considers the George W. Bush administration’s thinking on nuclear deterrence in the aftermath of the terrorist attacks of 9/11: What was distinctive about the Bush administration’s thinking and approach to nuclear deterrence? To what extent, and to what effect have the Bush administration’s approaches proved enduring? The article considers the prima facie contradictory nature of the administration’s deterrence objectives against the backdrop of a shifting security environment, characterised by the proliferation of WMDs to ‘rogue states’ and non-state actors, nuclear multipolarity, disruptive emerging technologies, and long-held US commitments to its global allies and partners—ensuring the centrality of nuclear weapons in US national security policy, despite sustained efforts to reduce this reliance.