The Joint Chiefs of Staff (JCS) is a body of senior uniformed leaders in the United States Department of Defense who advise the President of the United States, the Secretary of Defense, & the National Security Council on military matters. Established during World War II to advise the President regarding the strategic direction of the armed forces of the United States of America, the JCS continued in existence after the war and, as advisers and planners, have played a significant role in the development of national policy. The JCS also harbors operational command authority, both collectively as a whole and individually.