At age 18, John enlisted in the Missouri Army National Guard at the 1/128th Field Artillery, Battery B, in Kirksville, Missouri. John then served simultaneously in the Guard and the Army ROTC program at Truman State University.
After his Junior year at Truman, John was selected for early officer commissioning. During his Senior year, he served as a Second Lieutenant at the 1/128th while completing his studies. Upon graduation, John was reassigned as an Army Tactical Intelligence Officer (Airborne) and was attached to the Joint Special Operations Command (JSOC).