Why did Italy enter the war? The articles do not—and in 1915 could not—make any mention of the machinations by Britain, France and Russia that had encouraged Italy’s entry into the war. These countries had all signed the secret Treaty of London in the month before Italy declared war on Austria-Hungary. The treaty seems like a straight bribe: Italy enters the war and in return is promised ownership or control of territories that in 1915 were held or administered by Austria-Hungary, Germany and Turkey—all countries that Italy expected to defeat in war. The Treaty of London, by the way, was exposed when copies of it were found and published by the Bolsheviks after the October Revolution in Russia in 1917. By then the Italian army had lost almost 700,000 dead, had suffered one of the largest defeats in the war, and was close to collapse.
— source blogs.scientificamerican.com | 2015