The offensive that died on the Piave was doomed by its own leadership. Austria-Hungary's commanders could not agree on where to strike. Svetozar Boroevic wanted to cross the Piave and drive into the Venetian plain. Conrad von Hotzendorf, the former chief of staff whose disastrous campaigns on the Eastern Front and in the Balkans had already cost nearly a million casualties, preferred attacking from the South Tyrolean Alps. The two men despised each other, and neither Emperor Charles nor the new chief of staff, Arthur Arz von Straussenburg, could choose between them. So they split the army equally, giving each commander half the forces and abandoning the principle of concentrated strength that had made Caporetto a success the previous autumn. Straussenburg modeled the attack on Ludendorff's spring offensive on the Western Front, but without the element of surprise or the weight of numbers that had made that assault so dangerous.

On the Italian side, the disaster at Caporetto had produced something unexpected: reform. General Armando Diaz, who replaced the sacked Luigi Cadorna, analyzed what had gone wrong and concluded that Italy's rigid defensive schemes, overcentralized command, and lack of depth had made the army brittle. His staff developed a new mobile defense system that abolished continuous trenchlines in favor of recognized strongpoints between which even small units could move freely, choosing independently whether to retreat, counterattack, or call artillery support. Thirteen divisions, equipped with 6,000 trucks, were organized as a central reserve that could be rushed to any threatened sector. Italian intelligence also penetrated the Austrian planning: Diaz learned the exact timing of the attack -- 3:00 a.m. on June 15 -- and at 2:30 a.m. Italian guns opened fire on the crowded enemy trenches, inflicting heavy casualties before the assault even began.

Boroevic's forces managed to cross the Piave and establish a bridgehead 15 miles wide and 5 miles deep, but the river itself became their enemy. Italian artillery destroyed the pontoon bridges behind them, cutting off reinforcements and supplies. The Piave, swollen by summer rains, isolated large numbers of Austro-Hungarian troops on the west bank, stranding them under Italian fire with no way back. Many soldiers drowned trying to swim to the east bank. On June 19, Diaz counterattacked into Boroevic's exposed flank. Meanwhile, Conrad's thrust from the Asiago Plateau toward Vicenza met stiff resistance and gained little ground, adding 40,000 casualties to the Austro-Hungarian total. Boroevic was furious: Conrad, rather than sending his reserves to reinforce the critical Piave sector, had squandered them in repeated failed assaults on his own front.

The battle's full significance took time to register. In Italy, it was initially underappreciated, overshadowed by the drama on the Western Front. But the Austro-Hungarian Empire understood what had happened. Its army had committed its entire remaining strength in an all-out frontal attack and been defeated. The blow was not merely military but existential: the multi-ethnic empire's cohesion depended on the perception of invincibility, and that perception was now shattered. Conrad was dismissed from military service entirely on July 15. Four months later, at the Battle of Vittorio Veneto, the Austro-Hungarian army would resist for four days before collapsing as word reached its troops that the empire itself was disintegrating. Ludendorff wrote afterward that the failed Piave offensive was extremely painful and that he could no longer hope for relief on the Western Front from Italy. The solstice had turned the tide.