While the unification a Italy did effect world war one slightly, it had not nearly as much effect as Germany's unification. The Germans designed aggressive nationalism, started an arms race, gained territory and started a war they lost. .
This may have been due to the very different ways in which Germany and Italy were unified. Mainly democratically and politically Italy was joint with only two small revolts, whereas Germany's unification war made possible by three wars and much more blood spilt. Italy became neutral as the war stared giving up on the alliance with Germany, as they saw them as a danger to the peace. "The German's are not looking for protection as we do but are willing to risk us for their gain" (Roberto Galisti, 1914,p233) .
Most historians agree that nationalism (caused by the many revolutions) was one of the prominent causes of World War One. France and England were struggling to be seen as the dominant and most powerful country in Europe while Germany was quick to seek their place at the top to prove they were just as good as the older countries - no better. When people believe they are the best they want to prove it. "It gripped the men like a plague- as soon as they could they joint the armies to fight for their land and country" (Armach Van Hootsenburg, 1899, p141) .
Another major cause of the war was the arms race. Due to hostilities, nationalism and legislation passed in English court making it a law that Britain's navy must be stronger that two combined powers, an arms race broke out in Europe. Armies and navies were greatly expanded. The armies of France and Germany doubled in size between 1870 and 1914. (www.schoolspider.com/history/worldwar1) It was agued that with all those weapons the countries grew restless to try them out.
Because the general feeling of leaders back then was land = money = power all the major powers competed for territory in Africa. Germany went in full flag and took fair chunks of land; Italy got only a small slice of the powers pie-proving Germany as the aggressor of the two.