Military, social and economic historians have long appreciated the significance of the conflict in Korea in shaping the post-war world. The policy of containment was formed, China was established as an important military power, and the US increased its military expenditure fourfold as a result of a conflict which killed over 33,000 Americans. What has been less appreciated is the role played by the United Nations and the British Commonwealth in influencing US strategy at this time of crisis: the Truman administration invested time and effort into gaining UN approval for the conflict in Korea, and the course of the war was adapted to keep UN allies, often holding crucial strategic positions in other Cold War theatres, in tow. This groundbreaking study explores these fluctuating relationships, the tensions between Washington and its British Commonwealth allies and their impact on the development of the conflict, from its outbreak in 1950 to its end at the Geneva Conference of 1954. Robert Barnes reframes the Korean War for the first time in the context of a United States less dominant than is usually imagined. This will be essential reading for students of International Relations, Cold War Studies and modern History.