4. Italy Switches Sides in 1915
In 1915, Italy shifted from neutrality to join the Allies, motivated by promises of territorial gains from Austria-Hungary. The secret Treaty of London, signed on April 26, 1915, stipulated that Italy would receive territories such as Trentino, Trieste, and Dalmatia upon the Allies’ victory. This decision opened a new front along the Italian-Austrian border, diverting Austro-Hungarian resources and contributing to the Central Powers’ eventual defeat. (National WWI Museum and Memorial)
