The Treaty of London () or the Pact of London () was a secret agreement concluded on 26 April 1915 by the United Kingdom, France, and Russia on the one part, and Italy on the other, in order to entice the latter to enter World War I on the side of the Triple Entente. The agreement involved promises of Italian territorial expansion against Austria-Hungary, the Ottoman Empire and in Africa where it was promised enlargement of its colonies. The Entente countries hoped to force the Central Powers – particularly Germany and Austria-Hungary – to divert some of their forces away from existing battlefields. The Entente also hoped that Romania and Bulgaria would be encouraged to join them after Italy did the same. In May 1915, Italy declared war on Austria-Hungary but waited a year before declaring war on Germany – leading France and the UK to resent the delay. At the Paris Peace Conference after the war, the United States of America applied pressure to void the treaty as contrary to the principle of self-determination. A new agreement produced at the conference reduced the territorial gains promised by the treaty: Italy received Trentino and the Julian March in addition to occupation of the city of Vlorë and the Dodecanese Islands. Italy was compelled to settle its eastern border with the new Kingdom of Serbs, Croats and Slovenes through the bilateral Treaty of Rapallo. Italy thus received Istria and the city of Zadar as an enclave in Dalmatia, along with several islands along the eastern Adriatic Sea shore. The Entente went back on its promises to provide Italy with expanded colonies and a part of Asia Minor. The results of the Paris Peace Conference transformed wartime national fervour in Italy into nationalistic resentment championed by Gabriele D'Annunzio by declaring that the outcome of Italy's war was a mutilated victory. He led a successful march of veterans and disgruntled soldiers to capture the port of Rijeka – claimed by Italy and denied by the Entente powers. The move became known as the Impresa di Fiume, and D'Annunzio proclaimed the short-lived Italian Regency of Carnaro in the city – before being forced out by the Italian military so that the Free State of Fiume could be established instead. The Regency of Carnaro was significant in the development of Italian Fascism. Background Soon after the outbreak of World War I, the Triple Entente powers