He joined the military of the First Austrian Republic in 1934 and started to attend the Theresian Military Academy in 1935. Following the Anschluss, he was transferred to the Wehrmacht and received his commission as a second lieutenant. At the beginning of World War II, Spannocchi commanded a platoon that took part in the Invasion of Poland, in the course of which he was promoted to a first lieutenant. After various positions at both Eastern and Western Front and being wounded twice, he was captured by American forces in late April and became prisoner of war until June 1945.