Xu Shuzheng
In the 1919 Paris Peace Conference, Duan's ally, Cao Rulin, promised Japan all of Germany's concessions in Shandong. This sparked the May Fourth Movement which seriously weakened the Anhui clique's hold in government. Though the First World War had ended, the army Duan had created to send to the trenches was not disbanded. Instead, it was given to his deputy Xu Shuzheng to invade Outer Mongolia. This soured relations with Zhang Zuolin of Manchuria's Fengtian clique who considered such a large army bordering his territory as a threat. The Zhili clique demanded more influence in the government but in December Feng Guozhang died leaving the group momentarily leaderless. Cao Kun and Wu Peifu emerged as the leaders of the Zhili clique and they issued circular telegrams denouncing the Anhui clique. Cao and Zhang pressured the president to dismiss Xu Shuzheng. The president was already leaning against Duan for sabotaging his Shanghai peace talks with the South in 1919. Both Xu and Duan denounced the dismissal and promptly declare war on 6 July 1920. On July 14, the two sides clashed in the Zhili–Anhui War. Within a few days, the Anhui clique was defeated and Duan retired from the military. The new parliament was dissolved on August 30.