[1][2][3] Following the outbreak of the Italo-Turkish war, in 1911, he left for Libya as platoon commander of the 40th Alpini Company, distinguishing himself in Derna, during the defense of the "Lombardia" Redoubt on March 3, 1912, for which he was awarded the Bronze Medal of Military Valor.

On 4 June De Cia distinguished himself during the attack on the ridge of Mount Mrzli-Mount Sleme, earning a second bronze medal for military valor.

During the attack for the conquest of Mount Kucla he was seriously injured by a bullet in his chest, after which he was hospitalized for several months; he returned to service in March 1916, at the command of the 118th Company of the "Monte Clapier" Alpini Battalion, engaged in Val Fella (Carnic Alps).

[4][5][6] In May-June 1916 his battalion, deployed on the Tonezza plateau north of Arsiero, took part in the fighting to stop the Austro-Hungarian offensive launched by General Conrad von Hötzendorf.

From the month of July he participated in the counterattacks that lead to the reconquest of part of the lost territory; during this period he was awarded two Silver Medals for military valor and was mentioned on the Order of the Day of the French Army for his valiant behavior.

[12][13][14] In June 1940, after Italy's entry into World War II, De Cia took part in the Battle of the Western Alps in command of the "Pusteria" Division, deployed in the Colle della Maddalena area.

In January 1941 De Cia harshly criticized the conduct of the campaign against Greece, stating that he was no longer willing to sacrifice a single soldier or a single mule in that insane operation (he had already previously criticized the conduct of the operations against France); this resulted in his immediate dismissal, even though he was promoted to the rank of major general, and his replacement by General Giovanni Esposito was passed off as a routine change of command.

In January 1943 De Cia was given command of the 223rd Coastal Division, also stationed in Provence, for which he began a training program in collaboration with the German forces.

[19][20][21][22] At the proclamation of the armistice of Cassibile, on 8 September 1943, De Cia was at his headquarters, where he initially tried to resist the Germans who ordered him to surrender, but eventually desisted to avoid unnecessary bloodshed.