The decision by the People's Republic of China (PRC) to launch a war against Vietnam in early 1979 has not been subject to scrutiny until now. The decision was shaped in part by the deteriorating relationship between Beijing and Hanoi, by Vietnam's new alliance with the Soviet Union, and by Vietnam's regional hegemony, but it also stemmed from the PRC's effort to improve its strategic position in the world. Three events took place in Beijing in December 1978 that also had an important impact on China's decision to go to war: Deng Xiaoping's reascendance to the top leadership at the Third Plenum of the Eleventh Central Committee of the Chinese Communist Party (CCP), Beijing's adoption of economic reform as the highest national priority, and the normalization of China's relationship with the United States. Deng Xiaoping, as a chief architect of China's national strategy in the immediate post-Mao era, played a dominant role in China's decision to go to war.