This chapter explores Italy’s nuclear policy-making during the final phase of the negotiations leading to the conclusion of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The chapter deals with a time-frame starting in late 1966, when the Italian government was first apprised of the new US draft of the treaty, and concluding with the Italian signature in January 1969. The chapter’s main goal is to provide a plausible explanation for the Italian hostile reaction to the US proposal, thereby filling a significant gap in the historical literature. Other than my own, the only other available accounts are the contemporary works of the opponents or the supporters of the treaty. My research has been able to provide a more rounded account thanks to the increasing availability of a variety of Italian, US, and British primary sources.1 This chapter, in particular, is based on the personal papers of Aldo Moro and Amintore Fanfani (respectively stored in the Archivio Centrale dello Stato (Central State Archives) and in the Italian Senate’s Historical Archive), the papers of the Ufficio Disarmo (Disarmament Office) of the Italian Foreign Ministry (at the Ministry’s Historical Archive); the newly declassified US Arms Control and Disarmament Agency (ACDA) Director’s Office NPT files (Record Group 383) and the records of the Department of State (Record Group 59) at the National Archives at College Park, Maryland, as well as on a number of collections from the British National Archives at Kew.2