Why did Italy switch allies during the WW1?

Answer 1

Although the Italians were members of the Triple Alliance (Germany, Austria-Hungary, Italy) at the beginning fo the war, it delcared a neutral stance stating that the Triple Alliance was supposed to be a defensive alliance and Austria-Hungary was guilty of starting the war. However, after extensive negotiations by the Triple Entente (Britain, France, and Russia), Italy declared war on its former allies in exchange for the territories of Trentino-South Tyrol, the Province of Trieste, Istria, and Dalmatia should the German-Austrian-Turkish alliance lose the war.

Answer 2

Italy broke their alliance with the Germans and stayed neutral until a clear winner was present. they were brought over by the allies with promise of land, courtesy of Austria-Hungary after the war was won. Although allies won the war, but Britain and France didn't pay up. Hence WWII.