Promoted to lieutenant, he was designated for the Levant in September 1925 and was assigned at his request, to the 4th squadron of the 1st Foreign Cavalry Regiment 1er REC, with whom he took part to the columns of Hermon (French: colonnes de l'Hermon).

In 1932–1933, he pursued the course of an instructor lieutenant at Saumur, then joined the 1st Foreign Cavalry Regiment 1er REC at Sousse in October 1933, where he assumed the command of the 1st squadron.

He took part in the campaign of 1939–1940 at the general staff headquarters of the 20th Infantry Division (French: etat-major de la 20e DI), where he received a citation in June 1940.

Chef d'escadron in June 1941, he commanded the second squadron group of this regiment and took part to the campaign in Tunisia where he was cited at the orders of the armed forces.

He participated the preparation and realization of the 1961 general's putsch and joined général Raoul Salan at the corps of the Organisation armée sécrete (OAS) and took charge of the region of Alger then Oran where he remained until the end of June 1962.

Grand Officier of the Legion of Honour, Général Paul Gardy died in a car accident in Oliveros, Santa Fe in 1975.