Colonel John W. Hook was commissioned an Infantry Officer upon graduation from Officer Candidate School 25 January 1969. His first duty assignment was as Tactical Officer, 5Oth Company, 5th Battalion, The School Brigade, Fort Benning, Georgia. | His subsequent duty assignment include: Platoon Leader and S-1, 4th Battalion, 18th Infantry, Berlin, Federal Republic of Germany; Military Advisory Team, Military Assistance Command-Vietnam, Republic of Vietnam; S-4, Company Commander, S-3 Operations and Aide-de-Camp, 82nd airborne Division, Fort Bragg, North Carolina;  Recruiting Area Commander, Los Angeles Directorate of Recruiting Command, Los Angeles, California; Inspector General, Secretary of the General Staff, Battalion and Brigade Executive Officer, 3d Brigade, 82nd Airborne Division, Fort Bragg, North Carolina; Action Officer, Office of the Deputy Chief of Staff Personnel, The Pentagon, Washington, D.C.; Battalion Commander, 2d Battalion, 504th Infantry, 82nd Airborne Division, Fort Bragg, North Carolina; and Infantry Branch Chief, Officer Personnel Management Directorate, Personnel Command, Alexandria, Virginia. | Colonel Hook served as Chief, Combat Arms Division, Enlisted Personnel Management Directorate, Personnel Command, Alexandria, Virginia, prior to his retirement.