Sullivan culminated his service in uniform as the 32nd Chief of Staff of the United States Army—the senior general officer in the army—and a member of the Joint Chiefs of Staff. As the Chief of Staff of the Army, Sullivan created the vision and led the team that transitioned the army from its Cold War posture. In August 1993, President Bill Clinton assigned the duties and responsibility of acting Secretary of the Army to Sullivan, who continued to serve as chief of staff.