United States Under Secretary of the Army
The United States under secretary of the Army is the second-highest-ranking civilian official of the United States Department of the Army, serving directly under the secretary of the Army. The secretary and under secretary, together with two military officers, the chief of staff and the vice chief of staff of the Army, constitute the senior leaders of the United States Army.
Source: Wikipedia — United States Under Secretary of the Army (CC BY-SA 4.0)