The greatest threat to Western unity in the 1960s came not from a communist enemy but from an ally: France. Its imposing President, General Charles de Gaulle, launched an ultimately failed attempt to resist what he saw as a 'colossal Atlantic Community' by challenging American hegemony in the West and attempting to give Europe a voice in the Cold War. Using documents from both sides of the Atlantic, this book traverses the 1960s dealing with Western defence, Cold War detente and European integration to explore Anglo-American cooperation and the containment of the Gaullist challenge. It is the first detailed account of how the Atlantic Alliance and Europe featured in the relationship between the governments of Lyndon B. Johnson and Harold Wilson, and presents a pioneering analysis of how American views of Britain's decision to seek a European role and withdraw from east of Suez shaped the future of the Anglo-American relationship