. . Cadorna inherited a difficult political and military situation. The government of Prime Minister
Antonio Salandra favoured initial neutrality over Italy's treaty commitments under the
Triple Alliance. Cadorna was accordingly obliged to reverse long-established strategic plans and discovered that the army was ill-prepared for war against Austria-Hungary and Germany. In particular, large numbers of men and quantities of equipment had been deployed to
Tripolitania and so caused the home army to be disorganized. The Italian government declared war on May 24, 1915. Hostilities began along the entire front. Cadorna's plan included an offensive on the Julian front (main action), defense in Trentino (secondary action), and other limited actions in the area of Cadore and Carnia. The advance began from Cadore to the sea with offensive intent and in Trentino to improve the border's defensive conditions. The terrain along the Italo-Austrian border (from Trentino to the Isonzo) was unsuited for offensive warfare by being mountainous and broken, with little room for manoeuvring. In the first phase, from late May to late June, Italian troops occupied the southern part of the Trentino salient, the basins of Fiera di Primiero and Cortina d’Ampezzo, the border passes in Carnia, the Plezzo basin, and much of the right bank of the Isonzo; they also conquered Monte Nero (2245 mts), Monte Maggio, Monfalcone, Grado, Gradisca and created a bridghead at Plava. Cadorna then ordered a series of operations on the Julian front, where Italy could attack with two armies (the 2nd and 3rd) and Austria defended with one (the 5th). Despite the numerical inferiority of their troops, the Austrians were in a strong defensive position because of the nature of trench warfare, their optimal artillery and machine guns, and the local terrain disadvantaging attackers. Cadorna opted to attack mainly in that direction since the remaining portions of the Italo-Austrian front were judged even more prohibitive. After the Italian occupation of Sagrado and some other minor positions, the
First Battle of the Isonzo (from 23 June to 7 July) ended creating a stalemate, with high losses (dead, wounded or missing) on both sides: 14,917 Italians and 10,400 Austro-Hungarians. Between July 24 and August 3, Italy's
second Isonzo offensive took place. On the Karst, the Italian line advanced to the western slopes of Mount San Michele and east of Mount Nero. Italian troops made several tactical conquests and defended them from Austrian counter-attacks. The Italians gained Monte Rosso (2164 mts), Bosco Cappuccio and the nearby area, Castelnuovo, one of the two peaks (Hill 111) of mount Sei Busi, and the edge of the Doberdò plateau. The battle caused the two attacking Italian armies approximately 42,000 men dead, wounded, and missing; the 5th Austrian Army had over 47,000 casualties, losses that were judged "terrifying" by the Austrian generals in the aftermath of the battle. Cadorna ordered an operational pause to fill the ranks of the regiments with new reinforcements and wait for the arrival of field artillery. The so-called
Third and
Fourth Battles on the Isonzo formed a single offensive from late October to early December, with a six-day pause between November 4 and 10. The Italians captured tactically relevant positions, such as Oslavia (Hill 188) and Mount Calvario (Hill 184); they expanded their occupation toward Tolmino, made progress on the San Michele, and Italian artilleries were able to begin the bombardment of
Gorizia. In the two battles, Italy's two attacking armies (the 2nd and 3rd) suffered more losses than Austria's Isonzo army in absolute terms, though Austrian casualties remained worse in percentage. Cadorna, therefore, persisted in his strategy of attrition and commented "the current war can only end through the exhaustion of men and resources, and Austria is closer to reaching that point than we are. It is terrifying, but it is the way it is." After a fifth and short-lived Italian attack on the Isonzo, the Austro-Hungarian Army launched the “punitive expedition” on the Asiago plateau, in mid-May 1916, to push the Italians back into the Venetian plain; this attack was followed by an Italian counter-offensive. Cadorna then ordered that forces exceeding defensive needs be transferred to the Isonzo front, planning to take the fortress of Gorizia, the capture of which would permit the Italian armies to pivot south and march on
Trieste, or continue on to the
Ljubljana Gap. To counter the new threat, the Austrians attacked at dawn on 29 June, on the Karst between San Michele and San Martino, deploying poison gas for the first time on the Italian front. The
Sixth Battle of the Isonzo (6–17 August) led to the capture of Gorizia, the most significant success of Cadorna up to that point. Three more smaller battles were fought on the Isonzo in 1916 (the seventh from 14 to 17 September, the eighth from 10 to 12 October, the ninth from 1 to 4 November). With the arrival of winter, operations ceased along almost the entire front from the Stelvio to the sea. The first months of 1917 were marked by severe weather, particularly in Carnia and Cadore, with heavy snowfall. Operational activity on both sides was limited to artillery duels and small raids to maintain offensive spirit. In spring, Cadorna ordered the resumption of fighting. His
tenth offensive was fought from 12 to 28 May, during which the Italian army captured the Kuk-Vodice area. In August, Cadorna ordered the start of the
Eleventh Battle, which allowed the Italian army to break through Austrian lines in the Bainsizza plateau and advance for 10-12 kms. About 6 million artillery shells were fired on the infantry of both armies, and more than 38% of Austrian guns were put out of action. Fearing that they would lose Trieste in case of another Italian offensive, the Austrians requested support from their German ally to launch a preemptive attack. On 24 October 1917, a combined Austro-Hungarian/German army struck across the Isonzo at
Kobarid (called
Caporetto in Italian), and by 12 November, it had advanced all the way to the
Piave River. Cadorna's disposition of most of his troops far forward, with little
defence in depth, which contributed greatly to the Italian defeat at the
Battle of Caporetto; a responsibility also lying with other officers such as
Luigi Capello, commander of the 2nd Army, and
Pietro Badoglio, who was the corps commander in a sector overrun by the Austro-German attack. Cadorna himself had been on leave for most of October, and his immediate subordinate was seriously ill. The Italian Army retreated in disarray and seemed on the verge of total collapse; 275,000 soldiers were captured. On November 7, the Italian king and government dismissed Luigi Cadorna as Chief of Staff the Italian Army; Italy's allies Britain and France had also insisted on the dismissal of Cadorna and sent eleven divisions to reinforce the Italian front. However, those troops played no role in stemming the advancing Germans and Austro-Hungarians because they were deployed on the
Mincio River, some 97 kilometres (60 mi) behind the Piave, as the British and French strategists did not believe the Piave line could be held. The king appointed the respected General
Armando Diaz as Chief of General Staff, with Badoglio named as his second-in-command. Cadorna was reassigned as the Italian representative to the Allied
Supreme War Council set up in
Versailles. The restored Italian defensive line was held during the first and second battles of the Piave, and later served as a springboard for the
Battle of Vittorio Veneto, where the Austro-Hungarian army was finally defeated, after eleven days of resistance, by 51 Italian divisions, 3 British divisions, 2 French divisions, 1 Czechoslovak Division, and 1 U.S. Infantry Regiment. The Italians and their allies captured 426,000 enemy soldiers. ==Personal reputation==