In 1930, Theobald served as secretary of war plans at the Department of the Navy and as a member of the Joint Army-Navy Planning Committee. In February 1932 he received promotion to captain, and was Chief of Staff, Destroyers, United States Pacific Fleet from 1932 to 1934. He was a member of the advanced class at the Naval War College, engaged in a seminar study of "Japan and Pacific War" in 1934–1935, and was then put in charge of the College's Strategy Division.