Around the time of the death of Lin Biao in 1971, the Cultural Revolution began to lose momentum. The new commanders of the People's Liberation Army demanded that order be restored in light of the dangerous situation along the border with the Soviet Union (see Sino-Soviet split). Premier Zhou Enlai, who had accepted the Cultural Revolution, but never fully supported it, regained his authority, and used it to bring Deng Xiaoping back into the Party leadership at the 10th Party Congress in 1973. Liu Shaoqi had meanwhile died in prison in 1969.