In 1940, Kennedy attempted to enter the army's Officer Candidate School. Despite months of training, he was medically disqualified due to his chronic lower back problems. On September 24, 1941, Kennedy, with the help of then director of the Office of Naval Intelligence (ONI) and the former naval attaché to Joseph Kennedy, Alan Kirk, joined the United States Naval Reserve. He was commissioned an ensign on October 26, 1941, and joined the staff of the Office of Naval Intelligence in Washington, D.C.