In the quarter century after the founding of the People's Republic of China in 1949, Beijing assisted Vietnam in its struggle against France and the USA. Drawing on newly released Chinese archival sources, memoirs and diaries, and documentary collections, this book offers a comprehensive exploration of Beijing's Indochina policy and the historical, domestic and international contexts within which it developed. Zhai examines China's conduct towards Vietnam, providing important insights into Mao Zedong's foreign policy and the ideological and geopolitical motives behind it. Throughout the 1950s and 1960s, he shows, Mao considered the United States the primary threat to the security of the recent Communist victory in China and therefore saw support for Ho Chi Minh as a good way to weaken American influence in South East Asia. In the late 1960s and 1970s though, when Mao perceived a greater threat from the Soviet Union, he began to adjust his policies and encourage the North Vietnamese to accept a peace agreement with the United States.