He participated in the First World War with the rank of artillery captain, earning a Silver Medal of Military Valor for his behaviour during the retreat across the Tagliamento, following the battle of Caporetto.

From 1935 to 1937 he was commander of the 10th Artillery Regiment, and from 1937 he served first as Chief of Staff of the XX Army Corps stationed in Libya, then (from October 1939 to January 1940) as Chief of Staff of the 1st Army, then under the command of General Pietro Pintor, and finally as Military Attaché at the Italian Embassy in Washington DC.

He was then attached to the Ministry of War until in July 1943 he was given command of the 24th Infantry Division Pinerolo, stationed in Greece as an occupation force in the region of Thessaly.

[1][2][3][4] On 8 September 1943 the Armistice of Cassibile was announced, and within a few days, most of the Italian units located in Greece were disarmed and interned by the German troops.

[5][6][7][8] Infante's behavior in Greece favorably impressed the British, who in June 1944 repatriated him to Italy to take on the post of Deputy Chief of the General Staff of the Italian Co-Belligerent Army; he was also made aide to crown prince Umberto of Savoy, then Lieutenant-General of the Kingdom of Italy, in 1944-1945.