The valour which other Italian troops had shown during the summer and their success on the Bainsizza plateau had not prepared Italy or her Allies for so great a reversal of fortune in the autumn. The attempt after the fall of Gorizia in August 1916 to force a way to Trieste had been checked by the formidable bastion of Mount Hermada, and in May 1917 Cadorna turned to the other great obstacle to his eastward advance, the Selva di Ternova with its peaks M. San Gabriele and M. San Daniele, which dominated the valley of the Vippacco and the railway to Trieste running along it. But these peaks could not be taken by a frontal attack, and an effort was made to outflank them from the north by seizing the Bainsizza plateau and the Chiapovano valley behind it. A week from 14 May was spent in the preliminary operation of extending the Italian hold over the east bank of the Isonzo above and below Plava, and in seizing the westerly edge of the Bainsizza plateau with its two peaks, M. Kuk and M. Vodice. This advance over difficult country required great endurance and valour, but it fell short of anticipations, and on the 23rd Cadorna struck another blow in the direction of the Hermada. Hudi Log, Jamiano, Flondar, and San Giovanni were captured, and for a moment a footing was gained in Kostanjevica and on the lower slopes of Hermada; but an Austrian counter-attack on 5 June recovered Flondar and drove the Italians off the Hermada.
It was clear that Italy unaided could not achieve even the limited objective of Trieste on which she had set her heart, and in July Cadorna appealed for help to Great Britain and France. The former sent and the latter promised some batteries of artillery, but no infantry could be spared in view of our commitment to the Flanders campaign and of French caution after the failure on the Chemin des Dames; and in August Cadorna resumed his attack alone. It was dictated by political rather than military motives; for there was discontent in Italy which the most rigorous censorship could not conceal, and the reference in the Pope's peace note of August to "useless slaughter" evoked serious echoes in a public mind which found inadequate compensation for the meagre and costly results of the Italian campaign in its splendid advertisement by the Italian Government. Italy needed a victory, and Cadorna achieved enough to keep up the illusion of triumphant progress. The bombardment began on 18 August and the infantry attack on the 19th over an extended front of thirty miles from Lom to the north of the Bainsizza plateau to the Hermada and the shores of the Adriatic. Most of the Bainsizza plateau was overrun, Monte Santo at its southern extremity was captured, and the Italians recovered a footing on the Hermada. A terrific and bloody battle was waged early in September for the key-position at M. San Gabriele, but heavy Austrian reinforcements from Russia prevented the Italians from mastering the crest. On the 5th they were again driven back from the Hermada and San Giovanni, while away in the north they failed to take the heights of Lom. This held up their further advance across the Bainsizza plateau, and its eastern half, containing peaks a thousand feet higher than any the Italians had conquered, remained in Austrian hands. No real progress had been made, the partial occupation of the Bainsizza plateau proved useless, the losses had been tremendous, and at the end of September Cadorna reported that his main operations were at an end. Eleven of the sixteen British batteries were recalled, the French were countermanded, and the ball was left at Ludendorff's feet.