This book relates the development of Anglo-Australian-New Zealand relations during and immediately after the second world war to the role of the United States in the South-west Pacific. Based on the results of comprehensive multi-archival research, the book highlights the extent of American-Commonwealth rivalry in the region and following the crisis of late 1941 and early 1942 demonstrates how the reforging of imperial links was shaped by the expansion of American power in Pacific areas south of the equator. It provides an important and timely reassessment of the economic, political and strategic factors that led Britain, Australia and New Zealand to conclude that the postwar affairs of the South-west Pacific should be dominated by the British Empire.