This book is based mainly on government sources, namely material from the White House, State Department, Foreign Office (FO), Foreign and Commonwealth Office (FCO), Prime Minister's Office (PREM) and Cabinet (CAB). Private papers consulted include those of Harold Wilson, Foreign Secretary George Brown and Undersecretary of State George Ball. The book explores a period of the Wilson-Johnson relationship. It considers the seven weeks from Wilson's election until he went to see Lyndon B. Johnson on 7-9 December, a formative period in which Britain cultivated American financial support and which saw pre-summit diplomacy over the NATO Multilateral Force (MLF). The book covers the summit in detail, examining the diplomatic exchanges over the Vietnam War, the British commitment East of Suez and the MLF, as well as the interplay of personality between Wilson and Johnson. By exploring the relationship of the two leaders in the years 1964-1968, it seeks to examine their respective attitudes to the Anglo-American relationship. The book then assesses the significance of an alleged Anglo-American strategic-economic 'deal', Wilson's 'Commonwealth Peace Mission' to Vietnam, and another Wilson visit to Washington. It also considers why the personal relationship between Johnson and Wilson suffered such strain when the Labour government 'dissociated' the UK from the latest American measures in Vietnam. Next, the book addresses the period from August 1966-September 1967, during which Wilson launched an intense but abortive effort to initiate peace negotiations over Vietnam, and London announced plans to withdraw from military bases East of Suez.