Already trained as an artillery officer during his time at the École Normale Supérieure, Delsarte was put in charge of a unit in September 1939 which he commanded until August 1940.
Na sanay na bilang isang artilerya opisyal sa panahon ng kanyang panahon at ang École Normale Supérieure, Delsarte ay ilagay sa bayad ng isang produkto sa Setyembre 1939 kung saan siya commanded hanggang Agosto 1940.