Jean was conscripted in July 1949. At the end of his mandatory term in early 1950, he signed up for three more years in the military.

During the Korean War, Caporal Jean Drauden served with the second contingent as a sniper and rifleman. In addition, he was his section's second in command.

On 26 September 1952, at Chokko-Ri, the bunker occupied by Jean and his comrades Jean Simon and Marcel Feinen collapsed during a mortar attack. Simon managed to free himself, while Jean had to be rescued by Lieutenant Lutty and Sergent Mores. Private Feinen was freed last by Norbert Edert, Roger Feiereisen and Robert Hatto. Fortunately, Jean sustained only minor injuries.

After his return from Korea, Jean remained in the Luxembourg Army as a truck driver. In July 1954, he got a job as a customs officer in Frisange, where he stayed for two months. He was later assigned to the Service de l'Intendance. From 1955, he worked for the Luxembourg Postal Office until his retirement.