The US-Japan security treaty, which was signed in 1951 as part of the peace settlement following the Pacific War, has continued to the present to be the main basis for Japan's security and a key part of the United States' international involvement in east Asia. Although the treaty has been viewed as the outcome of discussions between the US and Japan, in fact, as this book shows, the British, then still a regional power with a continuing direct interest in Hong Kong, southeast Asia and the Pacific Commonwealth nations, played a key role in formulating the thinking on which the treaty was based. This book outlines Britain's role, discussing how Britain influenced US thinking on key issues such as how to balance any limitation of Japanese rearmament with the need to counter the communist threat, how new security arrangements concerning Japan should interlock with Britain's wider security interests "east of Suez" including security arrangements for Australia and New Zealand, and how far any Japanese rearmament should correspond to any German rearmament. The book continues the story up to 1954 when fuller security arrangements for the region, including the US-South Korea defence treaty, the US-Taiwan defence treaty and the Southeast Asia Treaty Organisation (SEATO), had all been put in place.