From 1932 to 1935 he was head of the III (counter-espionage) Section of the Servizio Informazioni Militare, and in 1935 he was promoted to colonel for exceptional merits and given command of the Carabinieri Legion of Palermo.

[1][2][3][4][5] After collaborating with the OVRA, in 1942 Pièche carried out an investigation on the proliferation of "parallel" police forces under the orders of the various Fascist leaders, on behalf of Benito Mussolini.

During this period he also headed an Italian military mission in the Independent State of Croatia and served as a consultant for the organization of the political police of Ante Pavelić; at the same time, however, he opposed the genocide of the local Jewish communities by the Ustashe.

He remained in territory controlled by the royalist government after the Armistice of Cassibile of September 1943, and on 19 December of the same year the head of government, Marshal of Italy Pietro Badoglio, appointed him Commander-General of the Carabinieri (with headquarters in Bari), a post he held until July 20, 1944, when he was made Prefect regent of the newly liberated province of Ancona and replaced by General Taddeo Orlando as Commander-General of the Carabinieri.

[1][2][3][7] After the end of the war in Europe, Pièche was prefect of Ancona until September 1945, and in 1946 he was appointed Director General of Civil Protection and Fire Services of the Ministry of the Interior.