After Yuan Shikai’s death in 1916, the next twelve years pitted regional warlords against each other for control of the national government.  This period of time is known as the Beiyang Warlord Era.  

China only had limited involvement in World War I.  Japan used the war’s distraction to strengthen and gain her foothold in China.  The Treaty of Versailles in 1919, ended the fighting in Europe.  During the negotiations China had discovered it had been betrayed by the western nations, Japan, and her own leaders.