Sidney Sonnino

Sidney Sonnino appears as Italy’s foreign minister at the center of the 1919 crisis over the postwar settlement. His departure from the Paris Peace Conference alongside Prime Minister Vittorio Orlando gave national disappointment a dramatic public form: a proud protest that rallied opinion at home, but could not compel the victorious Allies to grant Italy the territories it claimed.

The territorial dispute

The dispute joined two claims with different foundations. The 1915 Treaty of London had promised Italy Dalmatia if it entered the war alongside Russia, France, and Great Britain. Italian nationalists also argued that the principle of self-determination should bring Fiume, a small border city with a large Italian majority, to Italy, although Fiume was not included in the treaty. Their formula combined the treaty’s promises with the additional claim to Fiume.

Woodrow Wilson rejected both claims. On April 23, he bypassed Italy’s representatives and addressed the Italian people directly in a letter published in a French newspaper. The letter explained his refusal of Dalmatia and Fiume; in Italy, its paternalistic tone helped make the substance of the decision feel like a public slight. Sonnino and Orlando walked out of the conference the following day.

The walkout and its reception

The departure was presented as a proud, resounding gesture. Sonnino was reportedly said to have answered a diplomat threatening grave economic consequences by invoking Italy’s austerity and its familiarity with starvation. The reported reply cast the dispute as a test of national endurance, not merely a negotiation over borders.

At home, the gesture found a receptive audience. In the last week of April, Italian piazzas filled with demands for Fiume and Dalmatia, and the public rallied around its spokesmen in a shared sense of deprivation. The book places Sonnino’s act within a broader transformation of disappointment into national grievance: yesterday’s comrades, Italians were told, had refused what had been promised at the cost of 600,000 deaths. Ivanoe Bonomi described the conference as seeming like an ambush, while Filippo Turati warned in Parliament that the government’s buildup of public opinion could leave it no dignified way to retreat if no agreement proved possible.

Return to Paris and the cost of defiance

The walkout did not stop the negotiations. For fifteen days, Wilson and the other Allied leaders continued determining the world’s new borders without the Italian delegation, including the division of German colonies in Africa and the former Turkish Empire in the Near East. Orlando and Sonnino were then forced to return to Paris, eager not to miss the meeting with the German delegations. The reversal turned the initial display of defiance into a source of moral damage: the Italian public had been encouraged to believe that the country could stand alone, only to see its representatives resume negotiations without securing the rejected claims.

The episode defines Sonnino’s role in the book through a sharp contrast between the force of diplomatic theater and the limits of diplomatic leverage. His departure helped focus Italian anger and unite a broad public around territorial demands; the return revealed that this show of unity could not by itself alter the decisions being made by the Allies. As the train carrying Sonnino and Orlando entered Paris, Gabriele D’Annunzio appeared on the balcony of the Campidoglio, while his attendants spread a large Italian tricolor over the railing—a juxtaposition that keeps the national wound open even as the diplomats return to the conference.