This article assesses the role of the People's Liberation Army (PLA) in China's maritime affairs. A proper comprehension of Beijing's civil–military South China Sea strategy and the PLA's contribution to the formulation of this strategy is essential to a better understanding of Chinese President Xi Jinping's readjustment of China's South China Sea policy and China's assertive behaviour. This article argues that the PLA has been prominent both in policymaking at the top and in the first-line enforcement of Chinese maritime rights. At the macro level, the PLA's institutional authority is pivotal in overseeing the country's national security/defence-related foreign affairs. To Beijing and especially to the PLA, the South China Sea issue is regarded less as diplomatic and even territorial disputes, but more as national and military security disputes in the wake of US naval entry into the 12-nautical mile territorial sea of the China-held islands. The onus of dispute management now falls heavily on the PLA, and PLA centrality in the South China Sea affairs can be attributed to Xi's close ties with the PLA and his assertive leadership that gains firm support from the PLA.