 He thus recruited numerous new Communist party members from cadet ranks, and eventually set up a covert Communist Party branch at the academy to direct the new members.When Nationalists concerned with the increasing number of Communist members and organizations at Whampoa set up a "Society for Sun Yat-senism", Zhou attempted to squelch it; the conflict between these student groups set the background for Zhou's removal from the academy.Zhou participated in two military operations conducted by the Nationalist regime in 1925, later known as the first and second Eastern Expeditions.