Adan was defending the northern portion of the Suez Canal in the Sinai—occupied by Israel in its entirety during the 1967 war—when the Fourth Arab–Israeli War broke out in October 1973. During the war, he served as the commander of the 162nd Division, which suffered severe losses from 6–8 October during repeated attempts to stop the Egyptian assault and push Egyptian forces back across the canal. Later during the war, Adan led his unit across the canal and into Egyptian territory north of the Great Bitter Lake during Operation Stouthearted Men, and subsequently maneuvered his forces southward to Suez City, where they surrounded the Egyptian Third Army.