Fleet Admiral John "Mad Jack" McCain (May 2, 1986 – Present) is an American naval admiral and administrator. He served as the Chairman of the Joint Chiefs of Staff from 2048-2056 and played a prominent role in the Pacific theater during the Flood War. He received the Medal of Honor for his service during the Battle of Japan. He was the last of only seven men ever to rise to the rank of Fleet Admiral in the United States Navy, and the last Chairman of the Joint Chiefs to hold such a rank.