In 1921, Sadeh was a Haganah (Defense) commander in Jerusalem. During the 1929 riots he took part in the battle defending Haifa. When the 1936–1939 Arab revolt in Palestine began, Sadeh established the Nodedet ("Wandering Troop" or "Patrol Unit") in Jerusalem, that confronted the Arabs in their villages and bases. He demanded that his troops "leave the defences" and initiate military operations.