Abstract: In the fall of 1956, the Suez crisis caused a rift between the United States and its European allies France and Britain. As each country tried to come to terms with the meaning of Suez for their foreign policy, widely different visions of the alliance emerged in each country. In the years that followed, these competing visions of leadership within the alliance created tensions across a range of topics from nuclear policy to European integration and African decolonization. This dissertation uses a multi-national and multi-archival approach to reinterpret the history of the transAtlantic alliance from 1957 to 1963. Looking beyond Cold War-induced preoccupations, it adds to the current literature by bringing to the fore issues of economic and strategic interest, national prestige and internal alliance politics. Moreover, Diverging Visions of Leadership argues that the personal relationships between American presidents Dwight Eisenhower and John Kennedy, British Prime Minister Harold Macmillan and French President Charles de Gaulle largely influenced their actions and those of their governments. In elucidating the complex interactions of France, Britain and the United States during the period, it quickly becomes clear that many of the most interesting controversies occurring during this time cannot satisfactorily fit into the Cold War framework traditionally used to explain the period between 1945 and 1991. The British and French colonial retreat, their quest to obtain and maintain an independent nuclear deterrent and the efforts to unite Europe economically and politically through the European Economic Community, for example, have little to do with the Cold War, but remain extremely important to understanding the transatlantic relationship. I argue that diverging visions of leadership and struggles for power within the alliance itself, rather than the external threat of the Soviet Union, provide for a more complete explanation of the actions taken by the leaders of each country as they sought to steer alliance policy towards their own goals.