In 1962, Diem decided to split the command of the area in the south around Saigon into two, the former III Corps area being reduced in size to cover the area northeast of Saigon, and the newly created IV Corps taking over the west and southwest. Cao was promoted to general and assumed command of the new IV Corps Tactical Zone, which included the area of operations of his 7th Infantry Division. Command of the 7th was given to Cao's chief of staff, Colonel Bùi Đình Đạm. Dam expressed concerns about his own abilities when the promotion was first presented to him by Diem. Nevertheless, he took Cao's former position and welcomed Vann's advisers back into the planning effort. Despite the change in leadership, the same problems continued to plague the 7th Infantry Division.