Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, speaks with students and spouses attending a Capstone course at the National Defense University on Fort Lesley J. McNair in Washington, D.C., Feb., 27, 2015. The six-week course aims to make students more effective in planning and employing U.S. forces in joint and combined operations. The course also is mandatory for senior officers in the U.S. military.