China Gate and several other overseas Chinese websites translated an article from the Diplomat on Xi Jinping’s anti-corruption campaign in the Chinese military. According to the Diplomat‘s article, Xi Jinping’s decision to expel both Xu Caihou and Guo Boxiong from the Party for corruption "reflects his determination to put an end to the dominance of Jiang Zemin," who was the former chairman of the Central Military Commission (CMC) and general secretary of the Chinese Communist Party. Jiang Zemin promoted Xu Caihou and Guo Boxiong to the positions of vice chairmen of the Central Military Commission and Politburo members. "Guo and Xu continued to pay allegiance to Jiang Zemin even after he retired as CMC chairman."
Source: The Diplomat, July 31, 2015 & China Gate, August 3, 2015